There are some gaps in level 3 as I took the shortcut after not
 knowing what to do. Currently I'm stuck on level 6.
 
 Level 1: Intro (demo) First you have to deactivate the force field
 and let Mendell walk over the edge. Now you have two choices: towards
 a blue bridge and an upside down helicopter (mower). Take the first
 (easy) choice. Align the sliding blocks to make a bridge. After
 Mendell 
 
 A green bridge has appeared, but you need to deactivate the laser
 bars. Go towards the mower. With a bit of luck Mendell will walk
 towards the elevator to the second level. You can either make Mendell
 jump or change the direction of the mower which is muc
 
 Level 2: Chessboard Mendell will have to get past 6 rotating sliding
 cubes, but don't touch the wall elements. Next Mendell will have to
 bridge chessboard sliding blocks. Halfway he'll have to continue a
 level below Press the wall to deactivate it and let it move Mendell
 dow return to the upper level. Another chess bridge will follow and
 it will return you to the cubes. 
 
 Past the 6 cubes you will have two choices, but the brick conveyor
 belt (left) isn't active. Turn right towards the chess sliding blocks
 with a deadly moving pyramide. Bridge a gap like in level 1, but
 don't let the piramide touch you. A double piramide b blocks.
 Pressing a block will teleport Mendell, even if he is falling in the
 abyss. 
 
 This is nearly impossible to do so, but it will return Mendell in the
 end to the brick conveyor belt. Make a continuous bridge by clicking
 its pieces. Halfway Mendell will drop a level. Continue and at the
 end Mendell will be teleported to green acid wate
 
 Level 3: Air attack There's a shortcut if you activate the huge white
 elevator twice and take the proper green bridge. But follow the game
 and you'll meet an ufo. Destroy its missiles by clicking on them.
 I've destroyed a dozen or two without any results. < gap > Return and
 press the switch. The huge white elevator will take Mendell to a
 passage with each two green bridges. 
 
 Follow the green conveyor belts a couple of levels down and meet the
 blue sliding wall blocks after crossing a green bridge. Turn left and
 let the last block slide you down on another green bridge. Same
 problem, but it doesn't matter if you turn left or r
 
 Level 4: Lava pool Bridge the lava pool and let the red plate jump
 Mendell to a ledge Three red plates later and Mendell walk sover an
 edge onto a green ledge near a lava pool. take the right exit to a
 spiral stairway with red treads. When a tread is unlit you can change
 th 
 
 Continue to the lava waterfall and now Mendell must go to the bottom
 level using wall bridges on both walls. Some wall bridges are
 useless. Near the bottom move the wall bridge to let Mendell drop and
 quickly again to give him a little push so he'll land
 
 Now move the wall bridge and let Mendell walk onto it. To make
 Mendell continue lower the first block and activate the other 2 wall
 bridges. On the last bridge activate the bridge below and let Mendell
 walk onto the red board. Make Mendell jump and activa
 
 Level 5: Ice water The green conveyor belt will move Mendell over an
 edge at the end of a tunnel. Click the wall to move it back and
 Mendell won't drop on the cold water. There are a series of blue wall
 blocks towards him. Push each to let Mendell move to the exit on the
 le 
 
 Now you'll reach two helicopter blades You can only change the
 direction of them. Let Mendell walk on the first and move it counter
 clockwise. The second one must move clockwise. You need Mendell near
 the centre of the first one while the other sweeps him
 
 Level 6: Windmills Take the right elevator and open the gate to
 continue to the insides of a windmill. Basically it's the same puzzle
 as with spiral stairway except Mendell drops on the next tread. There
 are 4 windmills to cross, but from the second windmill you can choose
 
 The other elevator will lead to a bridge with sliding segments. Each
 segment slides completely under both wall sides, so be careful. After
 6 segment you'll reach 2 more and another passage in the same
 direction you came from. 4 Segments later and you'll l
 
 This will bridge the gap to the green conveyor belt. Mendell will
 walk through a green waterfall, drop to a level below and face a
 bridge with pulsating hot blue crystals. You can teleport to another
 one when it lites up. When it's deadly when its colour
 
 Continue and see the tiles behind you disappear. It's time for some
 more sliding bridges. The first one is easy, the next has a wall
 monster spitting sparks at you and the third lots of wall monsters. <
 gap >