Modern Sonic in Sonic Generations is looking pretty good...
Its the same as Colors. Which is to say bleh. And any attempt at 2D in SRB2 can tell you its just not that great. Its really basic and the control is awful in it. Your jump is often too short, and if you go too fast (which is easy to do), you can't stop until its far too late to not get hit or fall in a pit.