Great game, good coding, little if any bugs and just about the perfect difficulty ramp for mediocre gamers (I enjoy slightly harder games but it's not about me, me, me). You said that you wish to make better and more challenging games two things kinda wrong there this IS a great game and it's pretty hard to kill 4 guys while remebering to decapitate a moving target. Btw nice drawing what did you use to make them?
If you right click then hit rewind (any scene) then the scene's music will start play for as long as you play mix with other the other sounds. Did it in the kitchen scene and heard the fan all the time. WARNING! Game may crash!