It'd be nice if the UI didn't cover part of the play area. It's not a huge problem, but it can be a pain to click on colors hiding at the top or bottom of the game window without muting the game or switching colors.
It takes her a bit over 4 minutes to run 500 meters, according to a stopwatch and the 500 meter achievement. That's actually really slow, since sprinters usually run the 400 in about 1 minute, and an extra 100 would only take roughly 20 seconds. She's actually only moving at a speed of "slightly faster than walking but not even jogging" in game. :V
It's quite annoying when bosses are immune to or resist status effects, because it makes spells like "sleep" or "attack down" useless. No one ever uses them on regular guys who can be killed in two turns, so they're only useful for bosses. But they resist them, so they can't be used. Preferably make it so the bosses aren't immune to everything; I wasted a bunch of turns using all my nerfs.
Painfully annoying how there is no pause button. It makes leaving a mission/practice nigh-impossible without refreshing. Please add a pause button that doesn't involve leaving the screen with the mouse (which only occasionally works)