Great game!
I like it alot, i have played your previous version before and it turned out pretty good as aspected. Everything works perfectly and the fun factor is hitting the ceiling :P
I would be more fun if u put a little more options in hiding yourself from the enemy. hiding behind a rock and walk on the ceiling is pretty good, but blending in the background is not very challenging, because u can do it (almost) anytime you want.
the animation is a BIG PLUS, you did a very good job there! especially when u grab a enemy from behind and choke him :D his kicking legs were drawn very well (+)
the game control is pretty good, except the jumping to a higher platform is a pain in the ass. somehow it reacts a bit too slow on my command. Maybe u could improve that or something.
But beside all that it's definately 1 of my fav games all time :D