Thanks for your help Guizmus!
My character is supposed to walk on the blocks, so I can't change the floor collision box. But I use the same Enemy (Sprite) for all Enemies.
When you say "change collision box", how do I implement this exactly?
What I can think of right now is an invisible box with the platform behaviour where I put the actual Enemy Graphic and use an "On Every Tick" Command to place the Enemy Graphic on top of the Enemy Box?
But I just saw that I don't need the Platform Behaviour on the Enemies, since they don't move... My bad, It's a remnant from first design
So I can easily change the behaviour of the Enemies. only Condition they have to have is : On Collision with Player -> Destroy Player. But I don't think it needs a behaviour for this.
//edit: still not working with no behaviours (except Flash). So I think I've to go with the collision box change. Any further details on this would be very helpful
//edit2: ok, strange it's working now with
LayoutHeight - Block.Height - BlockHeightRandom + 40[/code:2u5xitoh], I tried with +20 and it didn't changed anything, so I reset to "+0" and all Enemies were floating over the blocks and +20 was the normal "on top of the blocks height" now, which makes +40 half the block size now.