I guess most of you will have a long way to go before this happens but if anyone has problems with the final boss I can help you.
The final boss is even a bit more difficult than the bosses before. It's inspired by games like Metroid Dread and Zelda BOTW where the difficulty is defined by the number of upgrades you collected. Every single upgrade will help to make him easier, there is even a hidden ability. I made sure that the boss can be defeated with 1 live and zero furballs, I already did that multiple times but you would have to be very skilled in this game to pull that off.
There are many different strategies for this boss but if you are almost giving up and don't want to collect more upgrades
go to my youtube channel Bobo The Cat [ Game ] - YouTube there you will find a guide with one of the easiest strategys for this fight.