Level-design-wise, Star Allies is like the Sonic Forces of Kirby... cuz a lot of levels are just too straight-forward.
But at least Star Allies brought in quite some new elements, which is what Sonic Forces didn't do. Sonic Forces basically just gave us what we've had in past games, but downgraded, and treat them like “new stuff”. You know how they brought in the Wall jump at the last Avatar-only level? I mean what the actual f-ck?