That's really addictive game! The gameplay is great By playing dozens of times and achieving 5 or 6 victories with positive HP, and more of that with 0 HP, I could say that the major challenge of the game is not about getting power and ruining enemies, but is about the simultaneous growth of potential and keeping it in check at the same time. The most painful losses occur when you encounter the King too early because of too too-powerful build for beginning levels (especially high-level Bard-Summonner/Ratfolk setups). The power of the King grew over time too, but not so fast as the power of the Witch, so, the strategy is about losing the minimum number of both red and blue hearts at each level to maximize the number of rounds before the boss battle. Nevertheless, there is another reason to keep growth in check. Level3 items are very powerful, but if you are creating L3 item when there are already 3 or 4 bones in the tub, your are getting one cool Tier 4 item (like jumbo milk or succubus or big boned) in the shop for it. But if you are crafting L3 item with 1 or 2 bones in the tub, you are getting some useless shit for it, like excalibur. So, that's another example, of when you should constrain your potential until the third bone is in the tub and not create L3 items, but just prepare for it. I'm interested if this encouragement for slow growth was intended or that's for coincidence, because seen something similar in roguelike card (dice) games, when you have good attack cards (dices) and can finish the round instantly, but the game encourages you to prolong the round as long as you can to heal it up until the end of the round (in that games that's a little bit annoying).
Here is a screen for my best run in the attachment. Managed to prolong the game for 12 rounds, and did the boss fight flawlessly (all the 3 lanes were mopped up with serious advantage). 3 HP were lost in the midgame. Maybe even when waited for three bones in a tub to craft my first L3 and make sure that I would not get lousy gift for it
PS: regarding the perf problems: I'm using Macbook m1 with 8GB RAM and after playing 3-4 games in a row without reloading page (pressing in-game restart button instead) the game becomes unplayable, - animation becomes slow, sound starts to freeze for fractions of a second. Page reloading tackles the problem. 