Good game. Got every upgrade, beat the king, completed every quest. Even got a few legendaries. Some improvements I see:
1)Making item sets more prominent. It took me 30 minutes after equipping all the gold armor to even notice they had a set bonus, or that set bonuses existed at all. Lean into set bonuses. More of them. Maybe have the items show what their other set items are, or have a third tab on that screen for discovering sets, maybe with hints. It can make finding and equipping all the set bonuses another long term goal for completionists, and give your game more play time.
2) Auto-Recycle. Similar to auto combine on pickup, I should be able to mark specific items I don't want for auto recycling on pickup, so they don't clog up the inventory. It can be a separate upgrade.
3) Full Screen Pickup. I agree with people saying there should be a late game upgrade that automatically picks up everything as soon as it drops, without having to mouse over it. The logic for this is for end game users grinding for the last quests or item upgrades. I'm not actively playing the game anymore at this point, I'm leaving the cursor in the middle of the screen until the round ends. Having to mouse over everything (as an end game player) is just leaving lots of items on the ground, not picked up, so I have to play more rounds to get the ones I missed. Sure, this pads play time, but in the bad way that isn't fun.
4) Recycle balancing. Currently, you're penalized for using the auto combine feature when recycling. For hitting the next level in your inventory, you get 1 item recycled for Common, 2 for Uncommon, 3 for Rare, 4 for Epic, and (I assume) 5 for Legendary. But the number of items it took to make those are: Common - 1, Uncommon - 3, Rare - 9, Epic - 27, Legendary - 81. So you're missing out on 6 points by recycling a rare. Heaven forbid you ever recycle something higher rarity than that. This ignores uncommon and rare drops, and the fact that auto-combining frees up inventory space for more items, thus the need to balance. As it stands now, turning auto-combine on gets you less leveling points than leaving it off.