Yeah, Kraid kinda lost his mojo after the first game, but this one turned him back into a proper challenge. I liked the way that fight ended, but given that he was already hip deep in magma, I'm not sure why dropping him a bit further was fatal. I've got a sneaking suspicion that he was either an optional boss, or could have been fought much later. I haven't run into much of anything that needed the diffusion powerup.
my only gripe at the beginning was there was a linear progression and very little time to explore areas and look for hidden paths or items. Not as linear as Fusion, but similar. As I went on it got better, as there are sections where backtracking is necessary but not obvious, so you’re required to explore.
It really does make you fight for everything you get...including the ability to move about more freely. At least it does open up abit quicker than Fusion, which kinda herds you for most of the game.
Making you fight for everything you get is kind of a double edged sword. On the one hand, I don't think I've felt such a sense of accomplishment getting a simple beam upgrade before. On the other hand, c'mon, game! Cut me a little bit of hugging slack!
The item pacing feels kind of weird. The spin boost is basically an altered high jump, but it comes much later than the high jump usually did, and not that long before the actual space jump. Likewise, the cross bomb is an interesting new ability, but I got it maybe an hour before the power bomb. I think that both of those abilities could have used some time on their own before a similar but stronger ability showed up.
The spin boost also needs something to differentiate it from the space jump. As is, it's strictly worse. Oddly, I could see it working in a Prime game as is, just being the double jump while the space jump gets turned into the proper space jump from the non-Prime games.