Gun-Nac review. br Shop CGR shirts, hats, mugs & gear! br It's always a great day to blow up demented space rabbits with laser beams while fighting enemy cigarettes, it's always a great time for Gun-Nac from Compile! It's not M.U.S.H.A., but it could be. It's a fabulously fun vertical scrolling shooter that reminds CGR of TwinBee, Alpha Mission II and Power Strike II.