Floor 40, got OP and bored AF.
The game is addictive, and has some nice, tho pretty basic concepts.
Here're a few tips on top of the ones mentioned by some other reviewers:
1.Make all skills dependant on your basic attack's stats, my making their stats a multiplicatives of the basic attacks. (Example: Say, Basic Attack deals X Damage, has Shot Speed of Y and Z Shot Delay, then Rapid Fire deals X*1 Damage, has Shot Speed of Y*5 and Z*0.5 of Shot Delay for it's whole duration)
2.Give all skills, including basic attacks, some floor-based/monster level based stat caps. Or cap the generation of certain items at certain floors/within certain monster level-range.
3. Make monsters increase their levels with each floor, making their stats, especially HP and damage, bigger.
4.Separate the items into types and make a limit to how much of different same-typed items a player can hold. Also give some items negative stats, on top of positive ones.
5.Make cap on additive stat-changing items, and make most of the said items into multiplicative.
6.Make scrolls only affect character's effects, while allowing the player to choose their own collor. Also add more scrolls.
7. Sometimes teleporting monsters and the chests tend to spawn in walls. Fix that.
8. Add some puzzle rooms. Take some inspiration from Gungeon and Isaac, if you have trouble with puzzle-making.
9. Add randomiser to chosen level-up traits. So level-upping can go infinite like the floors do.
10. Make at least 5 floor tilesets for all rooms, and some variations of said tilesets. And affix one music track to each type. And make some monsters, unique to said tilesets. Especially bosses.
11. Make more secret rooms, and make them more understandable ways to access them. I accidently accessed kings's crypt or something, took the crown, met the same room I used to access said secret room a few times, couldn't do that again. Also yah, make it harder to acess by accident, but leave some hints.
12. Make shops spawn on each floor and make money more valuable by either increasing prices/decreasing money spawn rate and ammounts of spawned or removing gold as currency all together and replacing it with current hp.
13. Make more different arrow types and make some of them combinable with each other, by either stats, effects or both.