Well, the first beta for kickstarter backers of Mighty No. 9 came out today, and I have to say... it was a ton of fun. The controls were pretty smooth, the graphics weren't too bad (though they could definitely use some touching up), and everything was just really enjoyable. It was difficult, but not crazy (and it was pretty generous on freebies before the boss, helping make it easy). I feel like with the way they have it setup, they can actual afford a bit more difficulty. To me, the boss seemed a bit harder than a MegaMan boss (though that could be because I'm rusty), but because when you respawned they basically gave you an extra life, they didn't have to worry about its difficulty sending you back to the beginning of the stage after a few tries. The boss took me quite a few tries before I got it down enough to beat it, so I think it was a decent adjustment.
There were a few bugs here and there, but that's to be expected with a beta.
Overall, I'm very excited about the game. It was a pretty solid beta.