You can move your guy with the arrow keys. Be carefull not to touch any enemies (all other moving objects are enemies). Some of them shoot lasers or auto-aiming rockets at you. Sometimes you see blue obstacles. You can remove these by walking over a switch (a gray/green square) but then other blue obstacles appear in another place. You can get some goodies from the treasury chest, like extra lives (hearts). If you have a gun, you can shoot some enemies by pressing space. If you have a bomb, you can blow up crumbled walls by pressing left-shift. A green arrow means that you can only walk over that arrow in the way the arrow points. The passage is blocked if you try to walk in another way.You can edit the levels with Henrik Stokseth`s level editor. There are some known bugs in the game though, the collision detection isn`t set right for some collisions.