Good game for short bursts.
Dungeon Hearts does one thing pretty well, but it quickly descends into grinding and carpal tunnel as you frantically move the mouse around trying to move the little dots into place to match 3. And yes, this is basically a match 3 game with an RPG skin on top. Graphics are ok, art style looks nice, but there isn't much more depth beyond more types of tiles and the stages going faster and faster. You play it over and over again, gradually getting better and occasionally getting enough XP for a permanent buff, such as 5% more HP for one of 4 characters. This was the first upgrade and it took an hour to get.
So I'd say it's a bit slow. There's a little bit of story there but the characters aren't really built up, so it's basically just window dressing. Mouse controls work, but as the stages speed up it gets harder to grab and move tiles, which quickly became agitating to me.