There's a ton of problems in this, I'm gonna list what I've found. I might eventually follow up with more, but this is what I remember

- Enemies that can climb on background walls have their stats rerolled every time they change between climbing and walking, which also fully restores their health
- Lihzarhds do the same thing at half health
- The icons in the skill tree ui can only be clicked near their edges, with nothing happening if you're anywhere near the middle (This and the last two were an issue in the last 1.3 version as well)
- Class selection isn't saved, so it needs to be reapplied every time you load a world. Needing to select it at all is also counter intuitive, and should probably be noted ingame somewhere
- About half the time when loading a world, it's like the mod just doesn't load, and you have to reenter the world. It only seems to happen once per session
- Weapon xp isn't saved properly, sometimes giving way more than you had and even going above what's needed for a level without actually getting it
- Transferring xp can ascend items without giving ascension points, leaving them permanently less powerful than normal. Also happens if an already ascended weapon is transferred to, just removing its points. Even undoing the transfer doesn't fix it
- King and Queen Slime don't spawn minions when damaged
- The stat ui's buttons make sound effects when moving the mouse over them while it's closed
- The ui in general needs work. The skill tree ones don't scale to high resolutions, the status bar's buttons are in weird places (Maybe also a high resolution thing), and the fact that buff and debuff icons are now rendered below the status bar instead of the hotbar means that they can't be seen if you have the status bar in the only place it looks good
- Enemies do WAY too much damage (At least on expert mode). I'm just before Plantera, and most enemies do over 3,000 damage, while I have something like 13,000 health. They also have too much health, typically well over 500,000, which even the Super Star Shooter with a ranged build takes like 20 seconds to get through
- Healing item tooltips are clearly supposed to show both their base healing and what it's adjusted to by your stats, but both shown values are the base one. That's the only issue, though, the actual healing works fine
- Hearts eventually become worthless, since their healing never changes from 20 and your health can easily get into the thousands