Yeah absolutely. It's also a great way to solve the chicken and egg problem of adding a feature which really sets Titan Attack apart and then that fills the lobbys more and that kicks off the virtuous cycle.

I asked because I have a start up called Asset Layer (https://www.assetlayer.com/) which built a backend solution for content and player management to make adding these feature super simple and affordable. It also enables UGC so you wouldnt have to do the design yourself but could leave the asset creation up to your community. Asset Layer would be especially easy to integrate for Titan Attack since we have an integration with Unity. 

I'd love to show you how our platform works and give a quick demo if you are interested!