I was pleasantly surprised by a game that takes inspiration from Isaac! I'm not the target audience due to that series' theme, so it was nice to have a Touhou counterpart. ^.^;
The visuals and audio all fit really well, too! I did notice that Reimu doesn't have any walk animations, although it didn't detract from the game at all.
This also isn't a necessity, although as somebody who enjoys Peglin, I do like how that game's items ("relics") have counters easily visible on the screen at all times, to tell when they'll proc next. If there's a way to somehow cram collectible items into one side of the screen, that might be a fun way to build on the Isaac formula.
Otherwise, the game had a lot of fun surprises, even from just the first floor or two (and a lot of attempts). This was excellent!