I just finished playing episode three and a half and really enjoyed it! I really love the free starter choice aspect, allowing you to choose your favorite or just straight up overpower your opposition from the start. In my opinion, this adds a great deal of replayability due to the current lack of availability of some pokemon outside of starter choice (r.i.p bagon line), as well as the ability to play some pokemon early. The ultra beasts seem a little out of place to me though, arguably being comparable to legendaries.
The difficulty also strikes a nice balance between the normal pokemon games and the more difficult fangames. Gym leaders do pack teams of 6 pokemon and rival/villain battles are more challenging than normally, but require no team changes or clutch strategies unless one is poorly prepared. I found the first gym much more difficult than all subsequent ones, though. Lack of time to prepare on my part and the use of non-evolving pokemon by the leader in particular contribute to this. (Do I need to spoiler tag this?)
I noticed a few potential bugs:
All in all this is a great fangame and I'll be looking forward to future releases.