Hey! Couldn't message you on Twitter but if you're still looking for someone I've probably got some stuff that might work - here's a link to my Soundcloud so you can see what I do :) Let me know if there's a particular vibe you're thinking of and I'll have a look at what I've got!
https://soundcloud.com/tethysaur
Most of my retro/chiptune stuff is down the page a bit - check out Empires, Coughing, and Unformed
Loving the look of the game BTW, excited to play it!