Wow, this is such a great little game. Nearly perfect. I love the little can-can dance animation, haha. The way that each group of dancers has different physics, and how all the game mechanics work together so well -- it's so good! Reminds me of Lemmings in a way.
Only two little suggestions for improvement -- and they're really only minor quality-of-life fixes.
1. It would be nice if the Arrow that shows which dancers you have selected would move organically/slowly when you switch -- this way my eyes can follow it on the screen and it's easier to know which dancers I'm controlling. As it is right now, the arrow just snaps immediately to the next dancers, and sometimes I spend about 2 seconds shifting my eyes across the screen to find the arrow.
2. It would be nice if there was a small transition animation when you get all the dancers into the curtain. Maybe have them all bow, then file into the curtains one-by-one (kinda like how the Lemmings exit the stage in that game). Right now, the the level transition is immediate, which also caused me a bit of issue because if I was holding LEFT while entering the curtain, it would immediately jump to the next level and my new dancer would start moving left before I even had a chance to look at the level layout! Not a huge issue, since I can just hit R to reset the stage, but it's a bit jarring.
Oh, and one more suggestion... more levels! I would love to just see more of this game in general. It's really fun. :)
Amazing work! 5 stars all around.