Many thanks to Piet B (piet.bossuyt@ping.be) and Gordon (glang@infobahnos.com) for supplying these cheats!
MDK - GAME WALKTHROUGH
WORLD 1…
ARENA 1: After landing in this arena, turn around and collect the "Most Cowardly Power-Up" to receive a health boost.
Run up the corridor and kill the waving guard with your chain gun, then wait for the next two guards and kill them both as well. Collect the "Worlds Smallest Nuclear Bomb" from the left side of the arena and use it to blow up the Atomic Lock on the exit door.
ARENA 2: After entering this arena, enter Sniper Mode and zoom in to the Guard on one of the parapets of the distant tower. Wait till he is holding the target over his face then shoot it to perform a "Head Shot". Repeat this for the next two guards who appear on the tower, then wait for the Exploding Crate to drop down and come to rest. Shoot this to blow up the tower and kill the three shielded guards, and then exit Sniper Mode. Collect the grenade which drops down into the arena then throw it at the red, glass wall (Making sure you stand quite far back when you throw it).
Now, stand on the top step in front of the pedestal and jump and float with your Ribbon Chutes to collect the Mortar pick-up.
Standing either on the pedestal or on the floor, enter Sniper Mode and target the black hole above the centre glass wall. Fire a mortar in to the hole and this will blow open the glass.
Run into the room and destroy the Guard Generator in the centre of the room. Use Sniper Mode to kill the three Guards with giant targets, by using the Head Shot technique, then collect the Dummy Decoy pick-up from behind the glass columns. Jump on to the lowest of the platforms and use the rest to reach the exit door.
ARENA 3: Stop after entering this arena and use Sniper Mode to zoom in on the distant building. Target the area just above the closed door, and you will see three of the Exploding Crates. Shoot any of them to explode the structure and blow open the door. Now run across to the buildings entrance, avoiding the Guards and the Tank as you go. Once inside the building, keep shooting the Guard Generator till it blows up to reveal the exit hole.
ARENA 4: Once in the Subway Station, destroy the Guard Generator to your left, then jump across the track and take out the one hidden in the alcove on the right. Collect the Grenades and then come back down to the Train. Cross over to the other side through the Train and approach the large door. When the Tank emerges, throw the Grenades at it repeatedly till it blows up. Run into the Tank's room to find the exit.
Arena 5: Kill the Guard at the start of this arena, then shoot at the Console to the right of him a couple of times. This will cause a Ship to fly down and hover in front of you. Walk into the Ship and you will enter Bombing Mode.
When in this state, you will be shown a view looking down at the arena with a targeting cross hair. The ship will fly you round the arena before dropping you back off at the starting point. While you are flying around, use the fire button to drop a series of bombs, positioning them with the cross hair. Destroy as many of the Guards as possible, and also bomb the top of any buildings you may fly over to blow them open.
When the ship has dropped you back at the beginning of the arena, move towards the building in the middle, entering the two on the right or left to collect pick-ups. When you get near enough to the last building, a Tank will be flown down into the arena. A second ship will then appear above the building and hover for a few seconds. Zoom in with your Sniper Mode and target the Exploding Crate hanging beneath it. Shoot this to blow open the door and then enter it. Destroy the Guard Generator and a Nuke pick-up will be revealed. Collect this and the Turkey health power-up, and then exit the building. Run around to the rear of the structure and you will see the Exit Door in the far wall at the back of the arena. Use the Nuke to open the Atomic Lock and then exit the arena.
ARENA 6: Follow the canyon passage in this arena to the right, be sure to take out the five Flying Guards before you get to the end, and then stand behind the last block on the right to shield yourself from the Cannon. Throw the Dummy Decoy to the left, and then shoot at the Cannon while it is distracted. If you have any grenades left, these will help you to destroy it faster.
Once the Cannon has been destroyed, jump up onto the block and enter Sniper Mode. Now, select Mortars from your sniper weapon inventory, and fire a mortar into each of the four "funnels". These lead down to the glass-fronted rooms and will blow up the four taunting Guards. If you do not have any Mortars, or you use them up trying, exit sniper mode and search the arena. There will always be a spare supply somewhere in the level.
After each Guard has been destroyed, the entire structure will explode to leave a chasm in the floor. Destroy the two tanks which appear on the other side of the gap, then stand at the highest point on your side of the chasm. From this position jump and float across to the lowest point of the other side. If you are lucky, Kurt will grab hold of the edge and pull himself up. Follow this section of the canyon and collect a Most Cowardly Power-Up to restore your health level.
Return to the edge of the chasm and drop down using your Ribbon Chutes to the bottom and the exit.
ARENA 7: Jump off the Glass Platform at the start of this arena, and float down to the floor, avoiding the spikes.
Use grenades to blow up the target dome in the centre of the room to reveal an Air-Vent. If you do not have any grenades, wait and a supply will drop down to you.
Jump on to the Air-Vent and you will float up with your Ribbon Chutes. When you reach the top of the air current, turn around till you are facing a long glass platform sticking out from a wall. Land on this and use the other Glass Platforms to work your way up to the top of the room. At the very top, collect the pick-ups and then leave through the exit.
ARENA 8: Follow the passageway round to the left and shoot the Alert Droid till it opens. Walk in to the droid, then drive it back down the passage and around to the door which leads in to the corridor filled with sentries. Now, while inside the Alert Droid, you can drive between them with trouble. Once you get to the end of the corridor, avoid the Very Big Guard and jump past him to the room beyond. Collect the "Worlds Most Interesting Bomb", and throw it into the centre of the room. When all of the enemies have crowded round it, press Enter on your keyboard to detonate it, remember to stand well back!
If any of the sentries survive, take them out with your chain gun till they have all been destroyed. Leave the corridor and collect the Nuke pick-up which drops down to the left of the entrance door, and use it to blow the Atomic Lock off the Exit Door.
ARENA 9: After floating up the air-shaft, stand on the highest section of the arena and face the distant tower above the glass walls. Zoom in to the Mine Controller who is working in the tower and select Sniper Grenades from your sniper mode inventory. Target the Controller's head and zoom in to the Max on his face. Now shoot him and, if successful, you will kill him with one shot. If you miss, or if you do not have any Sniper Grenades in your inventory, you will have to try again. Keep shooting at him with normal bullets and a supply of Sniper Grenades will eventually drop down into the arena.
WORLD 2…
ARENA 1: Wait for the Sniper Grenade that drops down into the rear of the arena, collect it then make your way slowly down the ramp to the next room. When you can just see the Floating Guard, enter sniper mode and target the Guard. Use a couple of sniper grenades in quick succession to destroy him, then exit sniper mode and shoot the Alert Droid. When he has been killed, the glass ceiling will break and allow the Worlds smallest Nuclear Bomb to drop down into the arena. Pick this up and then throw it at the door with the Atomic Lock.
ARENA 2: At the start of this arena, turn to the right so that you are facing the incoming fire, then use side-step to move left into the arena. Dodge the gun blasts, and work your way across to the other side of the shooting range.
If you fall into the trench that runs in front of the range, then run back to the left-hand side of the arena and climb up onto the block to reach the platform.
ARENA 3: Walk up to the top of the ramp in the centre of this arena, and wait for the Mortar pick-up to drop down. Collect this and turn to face the large glass wall. Enter Sniper Mode, and target the rectangular hole with the chevron edges. Select the Mortar from your sniper inventory, and fire one through the hole. The mortar will drop down to the Guards and cause the floor to crack when it explodes. A Nuke pick-up will then fly out of the hole and float down in front of the ramp. Collect this and throw it at the Atomic Lock to open the exit door.
ARENA 4: Walk up to the edge of the glass floor, then enter Sniper Mode and target the Grunt Foreman. Use mortars to kill him, then take out the two Warhead Carrying Grunts to detonate the missile stockpile and open up the floor. Drop down to the floor and then jump into the hole to reach the next arena.
ARENA 5: From your starting position in this arena, use your chain gun to kill the first Guard, then enter Sniper Mode and zoom in on the Second Guard hiding behind one of the far cannons. Use a Head Shot to kill him quickly, then walk down to the middle cannon with the Turkey Health power-up floating on top. Jump up on to the barrel to collect the power-up and then face down the length of the barrel. Fire repeatedly with your chain gun at the distant shooting range, and you will cause the cannon to recoil back of its housing and through the window behind the line of cannons.
ARENA 6: Once the cannon has blown up, float down to one of the floating platforms with your ribbon chutes. Once you have landed, use the rest of the platforms to reach the Exit Door at the rear of the arena. Be careful to avoid the three cannons at the end of the room. They all fire in a repeating sequence, so watch them for a minute till you know when it will be safe to move.
If you fall off while you are moving, there are two Air-Vents that can be used to reach the platforms. One is at the start of the arena, and the second is in the middle.
ARENA 7: Jump off the ledge at the start of this arena, then float down to the first of the floating platforms, where the Leaping Guard is waiting. As you float, shoot at him to make him jump out of the way.
From this platform you will be able to attack the leaping guard without being hit by the pendulum (if you move on to any other platform, the Pendulum will be able to strike you).
From this position, enter sniper mode and try to use the Head Shot technique to kill the Leaping Guard. Several shots will be required to destroy him. If successful, a ramp will appear leading to the Exit Door. Jump across to this using the platforms, being careful to dodge the Pendulum.
ARENA 8: Destroy all of the enemies in this arena and collect any of the power-ups that drop down. After a certain number of kills - it changes each game - a Worlds Smallest Nuclear Bomb will drop down somewhere into the maze of blocks. Collect it and move round to the back of the arena, behind the gigantic white tower. Kill the sentry and the two alert droids, then throw the Nuke onto the ground in front of the Atomic Lock. This will blow open the door and allow you to float up the inside of the tower to the Exit Door.
ARENA 9: After landing in this arena, walk round to the guard's Sky Sled landing bay and wait for one of the Sky Sleds to land. Jump on to the sled as the two guards jump off and turn round to face them. Shoot both of them with your chain gun till the have been destroyed. This will then activate the Sky Sled, which will take off and fly around some battle arenas, where the guards are practising their skills, before flying into the Mine Controllers tower. Once the Sled has stopped, it will drop you to the floor and allow you to enter the last arena.
For a bonus health power-up, wait at the sky sled landing bay and run into the left rear corner when it is empty. If you do this correctly, you will be teleported to one of the battle arenas. Wait for a moment, and one of the sky sleds will drop off the Most Cowardly Power-Up. Collect this and then walk into the centre of the battle arena. This will teleport you back to the landing bay.
ARENA 10: Follow the passageway up into the arena, then climb the ramp to your right to reach the upper platform and a health power-up. From this position, face the window on the other side of the room and enter Sniper Mode. Zoom in on the small alien and shoot once to break the glass. Now zoom in further and shoot repeatedly at the Mine Controller till he seals the window. For a bonus shot, try to target his nose and eyes!
Once the window has closed, exit sniper mode and wait for the controller to reappear in his glass ship. Shoot the ship repeatedly as it flies around the arena till it explodes. The controller will drop to the floor and run to each of the three doors in the arena to release a guard. As he runs, shoot him with the chain gun till his health bar is depleted. The Mine Crawler will self-destruct and carry you back into orbit.
WORLD 3…
ARENA 1: From the starting ledge, enter Sniper Mode and zoom in on the two Sentry Guns at the end of the arena. Destroy both of them and then exit sniper mode. Use the chain gun to kill the Flying Guard as it moves towards you, then float down into the arena.
Take out the first set of Guards with the chain gun, then position yourself in the centre of the arena and use sniper mode to zoom in on the two door stops that holding the large door shut In the distance. Shoot both of these off and the door will crash down and destroy the Sentry. Stay in sniper mode and head shoot the two Suicide Guards who come running out.
Next, find the ramp on the right-hand side of the room and follow it up and jump across to the upper platform. Kill the Leaping Guard which is standing there, and then climb onto the sloping platform on your left. Follow this up and jump over to the platform with the Super Chain Gun pick-up. Collect this and then jump and float across to the other side of the arena to collect the Bones' Air-Strike pickup. Drop back down to the arena floor and exit the level by the open doorway, killing any surviving Guards in the arena.
ARENA 2: Stand in the entrance to this arena and use sniper mode to kill both of the Sentry Guns. Exit sniper mode and use your chain gun to destroy the guards to the left and right of the entrance. Run in to the two alcoves behind the guards and collect the two pick-ups; Homing Sniper bullets and a Dummy Decoy. Drop down into the drained pool and collect the Super Chain Gun. Climb back out of the pool and kill all of the Guards who have dropped in to the arena. Once these have been destroyed, walk behind the diving board to find the pool annex. Kill all of the guards in here and collect the Apple health power-up. Wait for the two Flying Drones and the Sky Sled riding Guard to break into the room through the window, and then kill the two drones. Throw the Dummy Decoy back towards the pool area to distract the Guard on the Sky Sled and then enter Sniper Mode (making sure you are in a position to shoot his head. Zoom in on his face and perform a head shot to cause the Sky Sled to drop to the floor. Exit sniper mode and jump on to the Sled to collect the Worlds Most Interesting Bomb from the top of the room. Drop down the shaft to exit the arena.
ARENA 3: Kill both of the Sentry Guns at the start of this arena, then enter the glass tunnel. Use a Homing Sniper bullet to head shot the Guard at the end of the tunnel and to break it open. Float down into the room and make your way to the room at the rear of the arena. Collect the Twister pick-up and then use your chain gun to shoot each of the three Guard Containers till the break. When the last one is destroyed, the pipe leading back in the main room will turn green and shatter. Come back out and jump on to the platform in the centre of the arena.
ARENA 4: Collect all of the pick-ups in this tiny room and then shoot repeatedly at wall with your chain till the room breaks and reveals the arena outside. Use your grenades to blow up the seven Guard Generators in this room, at the same time taking out any guards. If the room gets crowded, use the Twister pick-up to destroy the guards.
Finally, kill the Sentry at the exit to unlock the door which leads to the arena.
ARENA 5: Walk to the edge of the platform which looks down into this arena, and then use Sniper Mode to shoot the two Sentry Guns in each corner of the room.
Next, jump onto the Blue Triangular platform to your right, and enter sniper mode again. Target the Blue Exit in the top right of the arena and wait for the Floating Sentry to appear. Now shoot him till he's destroyed - a good tip here is to use Sniper Grenades.
Drop down to the floor and collect the Most Cowardly power-up. Watch out for the Leaping Guards in this room. Try to jump in to the Blue Cave on the left hand side of the room and then pick them off from here. Once they have been killed, jump up to the left red cave and follow the red passageway up to the green platform. Destroy the Guard Generator and the Alert Droid, and then stand at the base of the arrow which points out into the arena. Follow the arrow by jumping across to the yellow platform in the middle room, Kill the two Guards here and then use the platform to jump across to the Blue Exit. If you failed to destroy the Floating Sentry at the start of this arena, then watch out when you jump into the exit!
ARENA