Pretty good, a little rough and bland, with a few minor glitches and annoyances.
In detail, I feel like the UI could use some work. Doesnt look very user friendly and is a little dry in my opinion. Its definitely to the point and doesnt leave any holes, just a little straining on the eyes. The white text on the light background is a killer, too :P
The game play is rough, I could barely get my knife to cut things, but then again, I was also playing on a laptop track pad. The concept is good, and it is fairly well executed. Could be made with a litle more umph, you know?
The upgrade system does well, and gives some variety. I also like how you had the different abilities too! :D I just think the flash ability is a little misleading. Its more like phase-walking through objects rather than flashing over them :P Unless you meant LITERALLY flashing in opacity, then I guess you win by wit, good sir ;) Still, my fav abilitiy, I must say.
The music works good with it, the sound effect are okay. All in all, I can give this a solid 3 stars. I think with a little work, this could be a pretty neato game :) Least more neato, ya know? ;D