Thanks! It is not precedurally generated in this build, but it is totally possible, because all the stages are already rendered dynamically according to a set of data that we manually created. There is actually a option for you to upload your own stages, but to unlock it you'd have to beat all the stages first ;D
All the stages data is generated from this JSON: https://github.com/blopa/mecha-mayhem/blob/0.0.1-alpha.4/assets/stages/stages.json