@KipgubbYT makes chiptune music, also @Sizzle_GT does (I know him), so one of them might be able to help. You could also try making the music yourself, Beepbox. The best and easiest music maker for games talks about Beepbox. 
If you want non-chiptune music, I’d suggest looking at Sharing my Music and Sound Effects - Over 1500 Tracks for free, commercial use music (requires attribution), he also makes commission custom tracks (not free).
There are just option’s I know, feel free to choose whatever music you want for your game!