Okay, if you playtested successfully, I defer to that. And good work being able to do that in the jam timeframe. I always just trust my instincts to get things approximately correct.
Where I was coming from is that 3D10 can potentially one-shot a character, and you can mind-control another. So worst case, in a single combat round, a typical four-person party could go down to two immediately, after which things would go downhill quite quickly. Bind could also effectively take one person out instantly, depending on whether "immobilized" means they can't move at all (e.g. attack) or merely can't move away.
Maybe I'm making the most player-hostile assumptions possible. If the song is in lieu of attacking, and her binding only stops movement actions, she's more manageable.
Regarding a "bottle scenario" I do think this is that. And I kind of did the same with mine... I like the minimalism! Maybe it just doesn't feel like there are enough strategic options for stuff to do inside the lander before jumping out to fight.