English version of the game, current ScummVM Git snapshot
If you use Flux on the cupboard at the foot of the stairs in the first room, Flux explains that he can't open it, but that he is a pretty good dancer. At this point, the game plays a brief drum riff and he's supposed to - but doesn't - do a little dance.
My only theory is that sys_Cmd_Play_Flux_Anim() currently is a no-op, and it does get called at this point. But if so, I have no idea what it's supposed to do.
There is another that I'm going to assume is missing for the same reason: After you repair the Chrurnatron, the cow and the sheep will thank you. The sheep isn't moving when she's talking. I've checked with DOSBox, and there she is moving. I'm attaching a savegame from right before repairing the Churnatron.
Scratch that. I restarted ScummVM and loaded my savegame again, and now the sheep was animated, just like expected. So I guess there is a bug lurking in there, but it's not anywhere near as easy to reproduce as I first thought.
I may have found how I got the bug to happen in the first place. In this new savegame, use the magnet on the haystack and then - without putting it away first - use the Churnatron part on the Churnatron. (In the previous savegame, I had already put the piece away.)
It also looks like I can only reproduce it if I press Space to skip Drew's lines. I don't know why that would also skip the sheep animation, which doesn't happen until a few seconds later...