Glad you enjoyed it and took the time to try out new builds :)
Yes, the game is not entirely skill-based, it's partly a stat check with some runs being more lucky than others, and that is by design, I'll keep it this way for now (I plan to have 4 difficulties + endless mode tho).
Actually there is saving (settings, coins, shop upgrades), unfortunately it is tricky on itch io to keep saves between different web builds. The desktop version doesn't have this issue. So whenever I upload a new web build, all saved parameters go back to default. I actually made some modifications on the ox boss and piercing sword behavior before your comment but I'm not updating too often to not reset the save states haha.
Attack speed is rounded on the stat sheet, and makes less of a difference the more you take it, so that's why you might have felt that, but I'll check it out. Bleed and lucky should work fine but I'll take a look at it.
I will definitely add a bestiary + found upgrades collection at some point. And yes, the bosses require a lot damage to projectiles, so that it requires a lot of investment/compromises to trivialize them.
Thank you for your feedback :)