First, compared to the first Naught, feels less floaty, like your character has more weight now. Also you can jump, which should open the door for some more complex platforming than the first game.
I prefer touch controls. The accelerameter scheme is weird because you have to rotate the entire device. That scheme lets you make much faster gravity switches, but just feels weird and unwieldly IMO. Touch controls are left/right rotate buttons on the left, tap to jump on the right. Animations have improved as well; Naught reacts to the changing angles (i.e. sliding down near vertical slopes).
Art style seems more textured and colorful than the first, and really adds to the atmosphere.
Gameplay so far is fun, nice level design. Replay value is in the form of hard-to-reach or hidden diamonds, and time trials for every level. Still need to get used to the new physics and controls after playing the first Naught all this week. No IAP
I don't know how it could be done, but I really liked the control scheme from the first Naught, with the left side rotating left, right side rotating right. If there's a way to have that button scheme, and add the jump function somehow, that's the scheme I'd probably use.
Each chapter starts off with a comic providing some story, but it's not clear that you have to swipe to change pages. I thought the game was stuck loading, until I decided to swipe. That might need to be made more apparent.
And as I said in my other post, I hope that control scheme prompts before every level are removed. Orborun had the same issue and it's just annoying. If anything, control options could be added to the pause menu, so players could swap controls anytime they want
Overall, I'm really enjoying the game. It's a big improvement over the first Naught and as a premium game with no IAP, with a good amount of content and more on the way, I'd say it's worth a purchase