I can help illuminate some details about this title, as reported by Justin Wong (AKA  the guy on the recieving end of EVO moment 37). Before I get into that, I want to briefly say that given the apparent lack of budget to use any new assets, I feel that they're doing what they can at the very least to make this stand on it's own from other versions of Street Fighter 2. I do think it's slightly ridiculous that they're doing this, and doing it with SUCH little fanfare.

*This game has throw techs. this is somehting that's in all Street fighter games 3 and beyond. this allows for escapes from throws by performing a grab at roughly the same time as your opponent. obviously this really only works on regular throws and not command throws like Zangief's Spinning Pile Driver.

*the level of input fudge from modern capcom fighters is present. combos seem to be easier to input because of adjustments made to hitstun and block stun. overall speed is different too. another thing to note is that balance is obviously different between the two art styles given that there's a change in aspect ratio

*Evil Ryu posesses Sakunetsu Hadoken, teleports, and a new command normal on ->MK that does a short leap and an overhead kick similar to an attack from the Street fighter alpha games. it uses the same animation as Ryu's jumping HK. He also has a raging demon, which is interesting because Akuma didn't get his own raging demon until Street Fighter Alpha, which was the third game he appeared in.

*Violent Ken makes his first appearance in a Capcom developed game (he was previously from the SNK Developed SvC Chaos, which is a terrible game). he has his command dash from there, which lets him move forward while being projectile invincible. also, street fighter 2 characters don't have a dash, so that's... honestly it seems kinda unfair to me? regardless, Violent Ken's Super is a lot like the sort of super moves you'd see in an SNK fighter, with it being a combo of normal attacks ended with a special.

*Balance changes that were made for Super Street Fighter 2 Turbo HD Remix seem to be ignored here, even if the HD art style is taken from that game.

*the codes for getting 'old' versions of characters that was in SSF2T was either not in the demo Capcom took, or is not in the game. Justin Wong attempted to play as the notoriously overpowered 'Old Sagat' and the button combination to select Old Sagat did not work. it could also be possible that this has been changed.

*Like Street Fighter 4, the game allows you to select character colors on the stick after selecting your character rather than with button combos and shows you what colors you're about to pick.

*Dramatic Battle is back from Street Fighter Alpha 3!

*there was a really strange bit in this game's trailer that cut to a 3D Model of a shadaloo grunt  and a POV Ryu giving him a Hadoken. There may be a LOT more to this game than meets the eye.

So the graphics in this are different than the Street Fighter II HD, right?

No, Shy Guy. they're the same graphics used in Super Street Fighter 2 HD Remix, which... I think actually came out in 2007. it came out before Street Fighter 4, and that game was 2008, so... yeah, `10 year old graphics.