I like it. It's a fun game, and as a Castlevania fan the messed up architecture seems really fitting.
My only negative is that a lot of the small 1x1 rooms can feel limiting. Sometimes my entire selection of rooms would be 1x1s even after a refresh. Maybe if there were more than 3 spaces available in the selection.
Also the bottomless pit seems impossible to build, but that could just be me being bad at the game. Not once was I ever allowed to place it, and I played some more after beating the game.