It's a pretty great fangame, with a lot of hazards that will only attack if you stay in place. There's a few bosses that are more crummily designed than others, but there's also a lot of work that looks professionally done. If you're looking for a Sonic fangame this is definitely one of the better ones, if not the best one. I definitely had a few issues with the game crashing and some bugs, so be warned!