I recently found a Sonic 3 mod called Sonic Tetris, a game where you can pick one of three games like the original Marathon, the one where you’ll have to clear all 40 Lines, and the first Sonic the Hedgehog with bonus Tetris levels.
I’d say this mod is 100% fun. 😀 Click here to check it out and subscribe it if you want to give this a try. All credit goes to Crash for making the mod.