I'm terms of other characters you're basically describing slay the spire which I love.
In terms of dungeon layout, they should be randomized you may have just gotten simple RNG.
The reason the town looks as lot better than the dungeon or the castle is because the dungeon was done in a 3 day period for the mini jam along with all of the base game mechanics. I spent a couple of casual days on the town then I ran out of time for the dungeon crawler jam and finished the castle and throne room in like 4 hours.
The original minijam limitation was 'you're not the hero' hence the alchemist being a bad guy.
The end text was literally just chat Gpt writing me an epilogue.
The castle music is also copy right infringement. Castlevania on the gb