Honestly a let-down. Expected better. Hero somehow dodges 99% of the moves at the end. On top of that, you can't attack much, and hero shouldn't be able to stand right next to you, or stand in the pole of the weapon when using 1 and not get hit at all. On top of that, he reacts before you even use the move, he dodges and moves out of the way right when you hit the key.
Issues that need fixing imo, especially if its gonna be on steam if you don't want a "mostly negative" review rating:
1. Moves are a bit sluggish
2. Hero is cheating, given he dodges and moves as if he can see the future. Super not fun, and does not give the proper "you're the final boss" experience. Makes it feel terrible near the end, especially with how he somehow adapts before even seeing the moves, if not just 1 or 2 times, which is humanly impossible when you get beat almost instantly those 2 times, giving you almost no time to even learn. Even pro players wouldn't be able to do that. Complete bs.
3. Unbalanced; hero gets tons of stuff, yet we have no counter, or any new abilities, or buffs, or anything. Our hp bar is in sections, yet the final one is all that matters. A true "final boss" would have a form for each section, not just the last. makes me feel the dev(s) have no clue about how 'final bosses' actually work, and just winged it with little knowledge whatsoever, especially how the hero can just stand in the handle of your weapon, or just on top of you for no reason and not get any damage.
4. plot armor; for being the final boss, its absolute bs that the hero just so happens to gain things perfectly countering you (ie; the shield near the end), negating a lot of the downsides without giving you anything. Ties into the unbalanced side, and the fact that the dev(s), again, have no clue how to design a true 'final boss' given how they should (and are) designed for end-game, and not "Oh, you can crush him early, but he overcomes it" which makes no sense, since you're supposedly the FINAL BOSS.
5. Final form also suffers from the unbalanced issues, and the sluggish issues. For as "final boss" (of which you aren't, given how underpowered you are at the end) it's just entirely not it, and needs some work. Not polish, but work. Actually fixing; not padding to make it seem fixed.
All-in-all, it's promising, but that's just it. So much for being "the most powerful being in the universe"
If this is gonna be on steam, there either needs to be difficulty options, or the dev(s) need to actually learn how bosses work, and re-balance this. It's pitful how OP the hero gets, especially compared to you, the "most powerful being in the universe", "final boss", or whatever you wanna call it. Makes no sense for the hero to just dodge every attack frame perfect, and sometimes just be immune to damage entirely. Glad I spent no money to play this. Would've made a refund if I did.
Last tidbit: overly positive community. I see little criticism here, which is bad. Constructive criticism is heavily needed, which I see almost none of, only people praising it here in the comments. Which makes little sense, given the above issues. And the ones that are get heavily downvoted, then met with dismissive comments. No, a "final boss" shouldn't move as if they ate a whole jar of pickles, nor should they attack slowly. A "final boss" should be quick and devastating, of which, this isn't (which is highly disappointing).
Final thoughts: This game isn't what it comes off as, and is a let-down if you care about gameplay. Story is nice, but I saw it marketed as a "you are the final boss" (which is 110% wrong), and I genuinely don't see the dev(s) fixing or changing anything to make it a more enjoyable experience, so this is more of a warning. So, go ahead, downvote me, dismiss all this, but I assure you it will disappoint a lot of people once released on steam, but I'm sure you white knights can handle it :)
Other than that, I rate this a solid -25/10, docking points for every issue above, and some extra for how the story and gameplay favor the hero. Will prob update this if/when these issues get fixed, and the hero isn't some cheating load of bs that insta dodged or gets free I-frames. Hope this serves as a warning for those not to pay money for this, or even waste your time playing it until the dev actually fixing the balance issues, as none of the other commenters are highlighting any criticism at all, acting as if it's a great, perfect game.