This screenshot from website Electricpig shows how a boss battle from the first Sonic game was updated for Sonic 4.
The targeting system allows players to "lock on" to targets when they jump. It is particularly useful for attacking enemies.
In the Casino Street Zone, Sonic can ride a deck of cards, which is one of the game's more memorable sequences.
Duck you sucka! The puzzle element of Sonic 4 has players do things like blow up walls by lighting fuses with a torch.
One of the best things about Sonic 4 is the game's menu. Players can select the Zone they want to play through and unlock each act as they complete it.
The Lost Labyrinth Zone shows off some of the most interesting platforming elements, like Sonic riding on a giant boulder and the mine car.