[User summary] Each level is a room as big as a screen (no scrolling). You have to leave the room before the time runs out, but initially the only door to do so is closed: you have to get the key first and only then reach the door. You may create or destroy blocks adjacent to you. Each room has already placed blocks, indestructible blocks, several enemies with different behaviours (static, respawning, patrolling, walking along the edges of the blocks, etc.) and a lot of bonuses (one-shot fires able to kill enemies, extra lives, extra score, etc.). Your goal is to leave all the rooms before losing all your "lives".