Hellooo I am Hebi-chan, the other person who has been working on this for the past few weeks.
If by theme you mean tileset, that would be amazing and would allow me to try my hand at mapping because I do not want to use the default FR/LG tilesets as I think they are overused and ugly. As for music, as Rot8er said in the opening post, we are looking for musicians so that would be very helpful! Although need the tiles and sprites quicker, having music in the work would not be a bad thing.
As for comments about Entropy being weird, most of the changes we made in fakemon and delta species are able to be turned off using the purity mode option. Additionally, mixed megas and dual type moves are both optional challenges. However, I find the game to be more fun with purity mode off and multimoves on myself.