Game is super fun, just suffers from lack of polish and performance issues. The gameplay is standard pokemon updated to modern gens, has the standard Kanto plot tweaked a bit to account for the fusion, and overall seems like a standard pokemon fangame. It's built off of essentials and rpgmaker so it's not quite a pokemon game 1-to-1, but it's just about there.
The fusion mechanics are awesome, although I wish there was a guide or better way to forecast it outside of looking up the information online. Fusing opens up a ton of opportunities and I greatly enjoyed all the custom sprite work people have put in to make certain combos come alive. The creativity here speaks wonders.
Overall this is a fun game that I hope gets fine-tuned in the future to make it more accessible and smooth since the core of the game is a standard fun pokemon adventure with a cool twist.