I liked the custom art, icons, and menus, but the art style kind of clashed with the RTP in my opinion. Not sure if there would have been a way to address that without a significant scope increase in either sourcing or drawing new tiles, but it's something to consider.
Tonally the bust/character art also clashed with the very dramatic music and dark-fantasy-inspired gear and skill names. As well as the story, come to think of it, but I'm less sure on that because I got a somewhat goofy vibe from the writing at times (not sure if it was intended). David seemed one-dimensionally arrogant, and Davina was almost exclusively a foil for that personality. I did get more "character" from the HTML crew, mostly along the familiar tropey lines we normally see them as.
A pretty basic "you're the bad guys" scenario which isn't bad per se, but it wasn't executed in such a manner that made me excited to see what happened next. I didn't get to the very end, because the enemies were very spongy and combat got repetitive quickly, with a slow trickle of new skills and occasional side-grade Equipment not being enough to keep me invested. A lot of things felt "off" in terms of battle balance, and many of the skills dealt exaggerated numbers of hits, so it was tough to parse how much damage was actually being done at any given time.
I actually liked being required to use Dispel Strike on the first boss, unlike some of the reviews I read after my playthrough. To me that was one of the better aspects of the battle system, and I wish there were more interactions like that instead of pure big-number spam.
Playing as a demon with an innate weakness to fire felt bad, and the fire mages liked to dogpile that character with their strongest skill. It wasn't unmanageable, just sort of a chore, as was learning that the Glass of Water item didn't provide any protection against being re-burned immediately, so it was almost pointless to use. Having to then Dispel Strike each fire mage in turn felt like just a more tedious version of the preceding boss fight, unfortunately. I think a new gimmick for that battle would've been advisable.
Overall I think this game might have benefited from being reformatted into a boss rush. There were a lot of encounters and most of them semi-trivial, which felt somewhat padded, but I could see it being quite fun given some streamlining and re-focusing.