Bumping this because I sat down to do some MP with friends tonight and wanted to say it was a BLAST, enough we played 12 or more games over 3 hours.
I'd severely under-estimated the scope of the power scale. When you've hit 800k, and you've racked up some combos, your attacks become screen incinerating explosions that no one can ignore.
There's also a lot of strategy to winning. Some people go all out and start attacking others full on from the start of the game, and get a few quick kills. But others quietly avoid conflict, building up their power over minutes slowly and then burst on to the scene one shotting everyone with their abilities powered to COMPLETELY broken heights.
And then the person who focused too much on killing at the start finds themselves at a 200k power deficit and unable to either hurt or resist the other players. Your power level starts to fall off over time, meaning unless you're killing non-stop, you have to reinvest a lot of energy into charging back up, to stay leader of the pack. And once you start killing people with impunity and god-like power, everyone tends to dog pile. It's sort of a self-balancing system. Playing against human opponents means investing TONS of energy into teleport dodges and always having to watch your back. Getting tunnel vision about the person you want to kill usually results in you getting shot in the back with an attack so massive there's no hope of survival. Or you get picked off by one of the dozens of homing-esqe attacks people can throw. To say you can corner fuck people in this is a gross understatement. Once someone towers over the other players at 300K+ power, they're able to kill almost anyone with one shot of their standard beam attacks. It's a big cat and mouse game that you become aware of when 80% of the screen is filled by an explosion or ball attack. You can of course cap power levels or start powered up if you want, so how insane matches get is entirely up the player.
Between friends old rivalries and antagonisms flared up immediately, cheese was called and everyone got tons of laughs. The game was good in SP, but it's a riot in MP simply because of all the "HOLY SHIT" moments you have, when an attack you thought you understood suddenly goes off at x10 the magnitude you expected. I'd thoroughly recommend this for a group of friends who likes beat em ups.
On the downside, we had a few crash issues and one hard locked my computer and windows had to do some recovery. So it's not problem free, but it's at least easy to connect.