My personal tastes lean away from experiences where I can get through a level and discover that I’ve made it impossible to continue, especially when it’s because I was too good (i.e., in the case of this game, I destroyed all the robots in the last stage). I know that’s kind of a matter of preferences, and in your game’s case, it’s honestly a minimal problem, since there’s a big friendly “press R to restart the level” reminder on screen, and the levels aren’t ever so long that it’s really painful to use it, but the frustration that does exist mostly comes from how long it takes the slower characters to get where you need them to go. That’s not really a problem on its own (it’s fun to accept that this character is slow because her legs are bound, or this one because she’s literally hogtied inside a weird cage thing), so it only becomes a pain point when it’s combined with a mandatory restart. In my humble opinion.
Viewing post in The Locked Valkyries jam comments
That's fair! It's similar frustration to the original Lost Vikings game that inspired this one.
I'll consider if there's a good way to get around that without breaking the core game design. I see the final level as a sort of "bad ending/good ending" scenario, but it's forcing players to get the good ending, which is an experience that could be improved.