Really good!
I'll hit on the Campaign first. It isn't really a campaign this time around, dialogue is zero, which I guess is good for a pure action game, but then you added having a partner, which completely takes away the need to fight anybody. The entire first zone was beatable with me only jumping around, I didn't have to fight a single person.
It got progressively harder, the main problem with the campaign is that there is no incentive besides medals to progress. Sure, medals are nice, but this game would do awesome with some sort of character progression.
I think my main problem is that not much was improved from the first Chaos Faction. While I liked it, the game felt really unresponsive at times. Sound effects are lacking in certain areas when they should be there and any fighting without weapons just feels plain weak. It doesn't feel like I've hit anything in particular when I smash a guy. Some enemies ignore your punches all together.
Also, some of the harder stages rely on plain luck. Some may be impossible depending on what weapons fall, but sometimes you can beat the stage in seconds, let's say, if you get an extremely overcharged weapon.
What I did like however, was the graphical improvements. Although the game kind of loses it's indie feel now, it looks really professional and the characters are pretty funky and awesome. The game is really action packed and a ton of work has obviously gone into this to make it as professional as it can be.
I remember playing the original Chaos Faction for around 10 hours because of it's glory, although I can't really see myself playing this version as it seems a bit uninspired. It's great, but it's missing a certain hook to it that the original version had. But anyway, great game, and I'm looking forward to seeing more from Dissolute in the future!
(also, your logo on the original is waaaaay cooler.)