Minimalistic and neat!

Cool game!

Fun game! It got very suspenseful towards the end of my session.

Fantastic little arcade-style eat-em game! Ramps up in difficulty pretty quick. One gripe: a game with only keyboard controls shouldn't require click to continue, maybe once for the title screen to give the window focus, but after that I should be able to hit a key to continue, especially in this kind of hardcore "one-more-try" type game, you're interrupting the flow by having someone leave the keyboard to grab the mouse.

Simplistic, but visually appealing. Gameplay mechanic wasn't too fun to play with, but the theme usage was fairly good.

Great little game. Controls were a bit wonky, and it eventually got a a point where there weren't enough color-changing pellets to even stand a chance (don't know whether that was intentional or not).

Spot on with the theme, gets hard fast.

Really minimal and neat! Ramps up quickly

Nice minimalistic gameplay.

Nice game. Took me a death to understand the game. (Who reads instructions? ^_^)

Great play -- though not clear enough at first how to use colour switch. Neat though.

The idea is good and well executed, but a small thing:

White and cyan look too similar and insta death quite punishing ;)

Sweet, simple game. Cool song at the title screen. Miss music inside the game, though. :)

Perfect scope for 48hrs. Gameplay becomes an interesting minefield--somewhat reminiscent of bullet-hell shooters.

Kinda wish there were some alternative to instant-a-death, but seems like this is likely just a matter of preference.
Would also prefer it if a differently colored enzyme wouldn't suddenly appear in front of the white blood cell while it's charging full speed; some sort of forewarning of the enzyme's appearance (and future location) or some placement avoidance of a radius around the player's position (perhaps with some consideration of current velocity) would be a nice subtle touch.

Thanks for all the great comments! I'm going to update the game with some of your suggestions. I especially like the idea of having an indicator of where the enzymes will show up.

My time was kind of limited over the weekend otherwise I might have been able to take it a step forward. Instadeath was something I tried removing but it became too easy so I'll have to figure out a balance. Thanks again to everyone who commented and voted!!