the control scheme is miserable and makes the challenges unbearably frustrating. there's a ton of randomness in this game and most of the skill is in overcoming the frustruating control scheme.
Collision detection is far too touchy with walls. Seems to count as a hit before you actually hit anything- maybe it's counting the shadows as collisions? Also, the scrolling in the large levels is poor, it should scroll ahead of you, not behind you. (you should see more level in the direction you are travelling, not less)
Needs a mute button. ;) but seriously... very aggrivating but addicting. Once you've figured out the patterns it gets a little less fun and a little more tedious, though. Wish the yellow balls didn't randomly fall from the sky.
endurance is pretty insane, I was doing good and then found out that extra balls can't fall out of play either- that seems excessively lame and unfair, plus unintuitive- no other game I know of works that way, you shouldn't lose a life until all balls drop off... Could also use a bit more color and some sound effects.
Definately too much luck, actually. Yes, you can accumulate bonuses early to plow through later levels but honestly, if a level requires by design a blue+green tile, and that tile doesn't come up any time before I've used all four deals, I've just lost to luck. Poor design.
Does get stale after a while, got a little tense near the end but still able to beat on the first try. Needs mainly to speed up a bit, try to get rid of the lag, and add a little more variety in the second half.
I'm also not entirely sure what all the available potions are nor what the enemy's weaknesses are even after beating it. Might be cool if it gave little callouts (and a log) as you discovered new potions, and gave some way to see damage being dealt or otherwise see which were most effective vs different enemies.