It's a neat game. Really nice to see something different for a change.
Maybe I'm just uncreative though, since in my view most of the abilities on the girls are pretty irrelevant. All you want are permanent buffs and multiplicative effects. Meaning pick up the whip girl who permanently buffs stats in either of her ability configurations, toss all the bonus xp you can afford her way and have her support the gangbang chick, whose early ability doesn't matter much as long as you get her double attack ability mid game. Then get the cowboy girl who equalizes stats and you've basically won, just pick up some other girls who support them and can handle other enemies now and then and try to find the item that doubles attack at the cost of setting health to one for the gangbang girl. At the end you'll easily have a front liner with 250+ attack and health.
Sure, that's a startegy that relies on pretty specific parts, but there's not that many possible options so doing a bit of rerolling seems to get it for you consistently. Granted, I've only done three runs on difficulties 1-3, but I don't see much reason to be going for anything else.
The UI is a bit unclear and cluttered, though. When I started, I had no idea what my resources were, since the circle with the info is so stylized that I didn't notice the number at the middle and I think I missed a tutorial message (Those need a box or something behind them, the plain red text just gets lost in the background). Maybe make the number a bit bigger and a different color? Also if you're not watching every scene on reruns, pretty soon the girls portraits are just big exclamation marks which doesn't look that great. Would be neat if you could dismiss those somehow.
I know this sounds negative, but I'll just repeat that I found this game a pleasant surprise.
Edit: Also, maybe add a wave number indicator so I know when the last one'll hit.