Don't let nitpicking reviewers steer you away from this faithful and fun sequel.
Most notably, the game is no longer linear, letting you choose which level you want to play via a world map. Game Over? No Problem! No more starting at the beginning, just pick up right where you left off thanks to a nifty thing called Autosave.
Nitpickers (GS Reviewers) will tell you that levels are unevenly paced, frustrating, and (my favorite) "dull". That's probably because Sonic is too hard for the people expecting to be able to run from A to B without any interruption. Get A Grip. This is Sonic people, and Sonic 4 has the pace of just about any other Sonic game. Fast, fast, platform, fast etc. It's not Mario Bros. The level designs are not difficult if you actually know how to play. The game can be cleared in an hour, showing just how UNdifficult the game can be. If anything, this is probably the EASIEST entry in the series thus far. However, the Final Boss fight is the one thing that will make you want to kill your system, being tedious and tiring before the real fight even begins.
All in all, this game plays and feels like the Sonic we grew up with, just with a shiny new coat of paint. If you were never good at Sonic before, you probably wont fair to well at this one. At First. The addition of a world map and the elimination of Game Over's make this the most accessible 2D Sonic game yet. Don't let other people tell you otherwise, Sonic 4 is worth the 15$.