I dumped a lot of hours into this for the first half of the game (I was actually choosing this over War of the Chosen) but I slowed down right before I hit world 3, and then revisited the game for a couple levels now and then for the rest of the game. I think in small doses, the end levels didn't grind me down. I can see that they might of had I been still binging on the game.
On one hand, I think a sequel that fixes some of the rougher edges could be amazing. On the other hand, I'm not sure the cross over gimmick could work a second time.
Underwhelmed's comments