Sonic The Hedgehog: Mania Edition

"Sonic The Hedgehog: Mania Edition" is a rom hack of "Sonic The Hedgehog 1" in which the level design, some animations and sprites of Sonic and enemies are modified to make it as similar as possible to Sonic Mania. The game is the same as Sonic 1 but the design of Green Hill has been modified to be similar to Sonic Mania.

Here they have added the Spindash because Sonic 1 did not have it, in addition the Drop Dash has been added, also you don't need anymore to go to the finish of the level with 50 rings. Now like sonic mania, you need to find the hidden giant rings scattered around the level