Pretty great classic experience, for the positive I'd say the way u unlock new abilities in this game is very well done, the levels are challenging and colorful, the robot masters are decently challenging but not absurd either without weakness. And also the way they handled the use of the 2 characters was very well done, it's pretty annoying when you have to go through 2 different campaigns just to play as the other character.
On the negative side, I think the game overstayed its welcome with over 6 wily stages... And I also believe rock's perk is way better than roll's. Charged shots come in handy in many situations and I don't think the double jump makes up for this disparity in power.
But still, the game was pretty solid and I will prolly come back to it as much as the official games in the future.

This game handles multiple playable characters better than any other Classic Megaman game in my opinion. The difference between Rock and Roll is big enough to where you feel like the choice is important and you'll have a preference but not so big that you'll go into some levels thinking you made the wrong choice or having one character be substantially easier/harder than the other. Outside of the character split I found the levels and boss designs to be not amazing or anything, but perfectly fine. It's a Megaman game so it's inherently fun regardless.
Definitely a good fangame, prefer it over quite a few official titles.