Played the demo for a week straight, wasn't hard deciding whether to buy it or not. I'm generally not a fan of roguelikes, but this game does everything right. Maybe I'm just a sucker for the party-based combat combined with the dice aesthetic. But don't be fooled by the luck-based dice mechanic- after playing for ~2 weeks, I can tell you I very, very rarely get screwed over by the dice, at least on normal and hard mode (I haven't tried 'unfair' yet). Because the player makes the decision on whether to reroll or not, you have a bigger part to play in what actions you take on any given turn. A large part of the gameplay is seeing what dice you rolled, how those rolls stack up against the enemy's attacks, and whether you should re roll some of them or not.
I might even go so far as to call this game a puzzle game, each turn seeing which dice will save you, and which are just better to reroll for something different.
Another bonus that you don't see on the store page (at this time) is a specific list of the alternate modes. One of my favorite modes is the 'custom' mode, where instead of having 1 of each class (like in the standard mode), you can pick and choose what classes you want in your party. You want to do a run with 5 healers? Go ahead. You want a full party of tanks? Why not. It's this mode specifically that keeps me coming back time and time again in between runs of the classic mode.
Taking breaks is possible, thanks to the game saving during every action, so you can put it down and come back right where you left off, which is especially good for mobile players.
The only changes I could see being good would obviously be more classes and enemies. Not that the variety isn't good already, but I figure the more content, the better. Another idea is adding another mode where skills are completely randomized for every class- like the level 2 healer classes could have any skills from the pool of level 2 healer abilities, rather than the classes having their preset skills. The mode could be called 'random' or something along those lines.
All in all, It's a crazy fun game, and $7 is more than a fair asking price. I mostly play on PC, but I also play on phone from time to time, and it handles really well on both platforms. I highly recommend you pick up the game, and I can't wait to see where the developer takes the game.