Not good. The mechanics aren't totally clear to me. You must line up carefully with the enemies to shoot, and can only shoot in cardinal directions (though there is a second attack that works diagonally). You shoot only down, unless moving, so you can't stop beside something and shoot. The levels are directionless, so you just wander around until you stumble upon the exit. In the second level (which is as far as I got), you have to keep retreading the same paths hitting switches to progress, and everything is very samey, so I wasn't great at keeping track of which path I should be going down.