Aside from supers, the way you attack is completely different with each…
There are far too many differences to go over each of them in a single thread without writing something the length of an article.
To just point out a few things, each character has their own unique moveset and normals.
I’m not really counting Sean, because he doesn’t have a fireball. He wears a gi and has an uppercut… Might as well call Dudley a shoto at that rate.
So all 3 have Hadoken, Shoryuken, and Tatsu, and all 3 have different properties on each.
Ryu and Ken’s EX hados are different, and Akuma has no EX.
Ryu’s Tatsu causes knock down, Ken’s is a multi-hit that doesn’t alter their state, and Akuma’s lifts them up for a juggle
Ryu’s DP is more vertical, Ken’s is wider and can be juggled (faster), and Akuma’s is somewhere between both. Ken’s HP also has that fire effect.
Unique moves:
Ryu: Side step kick, gut punch, collarbone overhead, useless target combo
Ken: Axe kick, step kick (and feint), REALLY GOOD target combo, and that mk anti air.
Akuma: Air fireball, red fireball, karate chop, demon flip and variations on that. Akuma also has 2 additional supers that can be used no matter which SA you select. (SGS and KKZ)
Akuma’s got a great sweep, low vitality, and huge mixups. You play him like a very rushdown-oriented mixup character.
Ken’s a rushdown shoto, but very linear in play. It’s like you play a good Ken, and you’ve played them all. Very few are truly innovative with him these days, but his tools are still amazing.
Ryu requires a lot of skill and zoning. Easiest of the three to learn, hardest IMO to master. You’re limited with your tools, so knowing how to select them in play is extremely vital.
All 3 have great dashes as well.
As for Sean, he’s got a lot of different normals, and that tackle. His uppercut sucks ass, his spin kicks are decent, his flip kick… idk… I’ve seen it used effectively at times, but I assume it’s really hard to use that well. Meh.
They’re all a lot deeper than this, but this is as much as I’m willing to write at 8:22am.