Congrats to you having a cooperative and talented team members! I was making my RTS game which attempting to bring some classic RTS mechanisms and attributes into it, but unfortunately, this is my first time to try to learn and make RTS game for this game jam, plus I had some busy stuff to deal with during the jam session.
In my game, only audio stuff were from external sources, others were made by myself. Despite this, my game still doesn't quite 'polished' as the enemy AI controls were done in rush, due to I wasted so much time on the coding of basic RTS mechanics, the auto-spawning resources and some GUI design.
Btw, hope this particular 4x-alike and RTS game can gain the ratings that it should be deserved!