Use the arrow keys to make Luigi walk. Use the SpaceBar to use your Poltergust, and use the mouse to aim it. Everything else seems self-explanatory, yeah. (I Fixed the Game so It's Playable Now! :D) (I Kept the Troll Secret in The Game. :3)
Credit to @scratchU8 for the Original Game. (If you See "Mario is Dead" on the Walls, Its the End of Beta 3.0, I Think.)