The more I play the Sonic 4 games, the more I realize how much more I would enjoy them if Sega took the Mega Man route in terms of game engine and visuals. If they're trying to recreate the hedgehog's former glory, why not bring us there in a very literal sense? Instead, we get a modernized 2D Sonic game that unfortunately gimps the legendary sense of speed that the early games were known for. I miss the days when the screen would visibly struggle to keep up with Sonic. The sense of pace is just busted; every tag team ability begins with an unnecessary flourish that wastes a few seconds of time. On the better side of things, level design is aesthetically superior to that of Sonic 4: Ep. I. This wasn't a hard feat to accomplish; after all, the developers literally ripped themselves off for the last outing. This spark of creativity can't save the level design, but I'm getting ahead of myself.
The sound design is more or less identical to that in Sonic 4: Ep. I. It's got the same comparatively charmless pseudo-16-bit soundtrack and the same sound effects. Nothing special here.