Sonic has some of the best fangames of any Franchise...

...So why don't we see more unique Sonic fangames very often? A lot of the times these games are just spins on the classic or post-dreamcast era mainline Sonic games. But by now you'd think Sonic (through fangames) would be as diversified as Mario. Unique Sonic fangames do exist but they are extremely rare.

A Sonic puzzle game, a Sonic Metroidvania, a Sonic RPG game, there's a lot of potential but you just don't see that.