My only complaint is that I find it a little bizarre that you require us to use the keyboard to advance to the next level, when you only need the mouse to do everything else. Otherwise, this is a great game, very unique.
It's so hard to know when you can actually "eat" other dogs, which is a bummer. Also, for future games, please put in a *real* mute button, that actually mutes everything. Also, I hate that I have to NOT pause the game to "mute" it...as in, I hate that the "mute" button becomes unavailable when you do pause it.
Whenever you choose an upgrade, and then get bumped back down a level, I wish you could choose a different path whenever you level back up. Other than that, awesome! The armor games exclusive stuff is sad, though. :(
The combo system seems rather buggy to me. I mean, I could write perfectly and super-fast, but with too much time between opponents, the combo is broken. It would make a lot more sense to me to have a combo system that is based off of skill, rather than simply timing it. For example, the multiplier goes up by one per enemy defeated, but the combo is broken whenever you type a wrong letter.
Awesome game, rather reminiscent of Four Second Frenzy. I did notice a glitch, though, on the blue level that's like Falldown, in the top left, sometimes the ball would ghost through the floors at higher speeds. Also, a number of the grid blocks didn't seem cropped quite properly.
Why do I need to click when it's only an arrow-keys game? I'd rather see it replaced by pressing Enter. Also, it'd be nice to have a way to distinguish the head from other blocks, and maybe have the target block be a different color. And I second Dogod, having the wraparound makes it too easy.