This is one of my faves so far for sure! At first I thought it was just ok during my first run, and that it was a little annoying how tanky the orcas were. But upon dying and realizing there was an entire tech tree, I was really surprised!
Immediately I felt engaged and spent time grinding out the money to get the engine upgrades and torpedoes, which felt good to use against the orcas that gave me so much trouble in the beginning.
I was a little disappointed to come to the realization that there was no actual end to the cavern, and that it just endlessly looped (unless there is, in which case sorry!)
A piece of feedback I'd give is that enemy variety is important for a game like this, atleast to me. In the context of a game jam, a quick and dirty hack you can utilize to get atleast *some* variety is to slightly randomize the size of whatever enemies you face. And in this game, slightly randomizing their speeds would have helped avoid them all clumping up together into big orca masses, and would provide some extra engagement in that players would want to target the faster ones first!