It does everything needed to satiate the needs of those who backed the game, but nothing more.
Speaking as someone who backed the game and got the PC version (I initially selected Wii U but changed my mind due to modding potential in the PC version), I feel like there's something they promised in the Kickstarter that they failed to deliver on.
So what makes Mighty No. 9—the character as well as the game—different? Simply put: the ability to transform! Of course our hero, Beck, earns new weapons as he defeats each of his fellow Mighty Number boss robots, but more than that, his body itself can also reconfigure into new shapes, allowing for all kinds of new skills and abilities!
Transformations were supposed to be the thing that made the game different, but the transformations we ended up getting in the final game were purely aesthetic. You could put Mega Man in there with basic palette swaps and it would play exactly the same.
What really makes the game different is the dashing and assimilation, yet the marketing seems to emphasize the transformation aspect.