Thank you for your prompt response and game updates. It shows you are developers who care about the quality of your games and that you're not the "fire and forget" type. I appreciate that, so I have given you the $333 you need to reach your goal. =) I haven't donated through Itch.io before, so please let me know if you received the money. What kind of boss fight will Sedusa be, if I may ask? How will it function? Also, out of curiosity, do you have any other goals after that one?
In trying to recreate the milk carton bug I had previous described, I found another one: if Robin drinks the milk within a second or two after getting hit, she becomes completely unable to move or attack. What's more, when she shrinks back down to regular giant size, enemies will pass through her and not deal any damage. The only way to fix it is by refreshing the page and restarting the game. On a related note, I've also noticed that sometimes the page needs to be refreshed either once or a few times for the game to run at all. I don't know if that's just a problem on my end or if anyone else has encountered that.
I also encountered another new bug when playing through the game again: the first time I entered Mojo Jojo's boss fight, the visuals were incredibly laggy to the point where they barely updated at all, but I could still hear the sounds of the boss fight happening so the game was still running mechanics-wise. When I inevitably died, the game then crashed. It worked fine the second time, so I don't know if that was a once-in-a-blue-moon bug or something that could happen again, but I thought I should let you know regardless.
Regarding the sound issues, I am using Firefox so perhaps they only affect that browser. Also, there's a Broccoloid right near the start of the first level, so it's very easy to see him suddenly scale up in Robin's hand when she's super giant there.
As for the combo system suggestion, I can understand wanting to keep the user interface as clean as possible. Perhaps, if your programmer doesn't want to use bars or numbers, they could try varying the impact effect when hitting enemies by using different colours and/or shapes to convey an increasing combo streak, with it resetting back to the default yellow four-pointed impact effect when the combo streak is broken? They could then have the score and any relevant details placed in result screens at the end of levels to really convey that old-school flash game arcade feel, with a final results screen when the game is completed. That'd be a way to convey the required information to the player without cluttering the screen with any additional user interface elements.
Thank you for taking my feedback on board and I'm pleased to hear that you're planning to further improve the game. I hope my donation will help with that. Oh, and, Merry Christmas. =)