I like what the game is going for, but it's in a pretty rough state at the moment. I know that might be obvious since it's labeled as a beta, but it's because of that I don't want to pull punches since I want this game to get built up into something great. I'll try to just hit on the important stuff to keep it as short as I can.
The controls felt very frustrating and confusing to deal with. Having something as simple as dropping down a platform requiring you to press three keys simultaneously felt pretty crazy considering that most games require you to just press down. Blocking as well had you do a crazy combination of buttons, and getting used to doing those buttons in the heat of battle is nuts. Speaking of blocking, I know you make them press three keys to drop down because block shares buttons and you want them to be able to block without dropping down, but in that case, why didn't you just make block a separate button, like holding F, so it's not an issue in the first place?
Even once you do accept the controls for what the mess they are, the precision required felt very frustrating: there's no input buffering so I found myself dropping combos constantly because the timing required was too tight that even mashing didn't help. Some fighting games do look for you to require precision, but I feel like a party game like this should opt for buffering to reduce the skill floor. Finally, I didn't like having to deal with so many cooldowns on abilities: I don't know why they existed since it slows everything down and it was difficult to tell when you were on cooldowns since you have to look at the way down in the corner (maybe play a sound or flash red or something if you attempt to use an ability on cooldown).
The game is also very dry at the moment. While you do have some slight special effects here and there, like puffs of smoke for running and fancy attack animations, there are no sounds or impact to it all. When fighting, it's very unclear whether you hit or get hit because there's no feedback like a sound or a spark or something: just feels like everything is punching at the air. All in all, it just leads to the game feeling very muted and unsatisfying.
I'd like to say that, despite my criticism, I still think it's very impressive that you created a multiplayer online game: lord knows I wouldn't do that since I don't want to deal with that level of complexity. And while I do think it's impressive you put that together, I still found it very janky. I had plenty of times where I tried to play only to go into some dark void softlock where I could never spawn, or if I did actually get in a game, we would just have out attacks phasing through each other without getting hit (though again, this could just be due to the game having very bad feedback/controls and not necessarily a network issue, it's unclear).
Again, I do think the game is interesting as a concept: you got a lot of potentially cool characters and I love a multiplayer brawler. But it's just very rough and I hope the feedback I provided can help you polish it up.