What finally did me in — and I made it past the video gaming war crime that was the bouncy maze — was the pirate bridge. If this was one pain point, I might have persisted, but it was the accumulation of them.
I've played pretty much everything you've released, and they're often outstanding in terms of design. There are some decisions on this one that I just don't entirely understand.. If there are sections that are going to pile up attempts (eg the surfing, the checkpoint races, the booster slaloms, etc) it's super irritating to have a multi-second flying saucer interlude and then get placed quite far away and, in the car sections, to have my car almost always pointed in the wrong direction as if it's going to drive off screen.
Maybe it's just not for me, but I'll still look forward to the next one :)