The screen monitor effects are really cool! I liked the variety of weapons, powers and levels- it got me playing through the game more than once to experiment. Lots of fun!
found a neat trick with the flamethrower, you can switch weapons while firing and the stream will stay active, you can combine it with the gun laser to melt the boss in seconds. The shield is also really strong, it ignores all the boss attacks and you can kill him before it expires.