Good job creating some good contrast with only two tracks, they both feel different but connected. The backing vocals did help with the pirate vibe you were going for. Even if you don't sing well you can make it quite convincing with some if you do many takes and spread them across the stereo field (plus some EQ + reverb to position it nicely in the mix). Might be a little too time consuming for a game jam so I imagine you did enough to meet the time constraints. Anyway, I found the soundtrack to be well composed, there's a lot of development and it never settles into a predictable pattern.