Found some beta footage of R3
I only saw the first one, but I see a lot of notable differences from the full version. Like that power up intros happen each time you get the power itself. I guess it was removed to keep the pace of the game moving.
EDIT: I just saw the second one, and it had a beta trailer at the end. But what's weird though is that the part where Rayman get's the grimace power up from R1, he actually literally changes from his R3 design BACK to his R2 design after he spins around to look at the screen. o_o Does that mean Rayman was going to transform back to his R2 form for some reason in R3? ._o I'm so confused...