Sonic the Hedgehog single-handedly made Sega a console powerhouse, so it s no surprise that they ve just finished porting their entire Sonic on Genesis library to the Xbox Live Arcade.
In an example of how old IP can still create opportunities on current consoles, Sonic the Hedgehog still satisfies (not critically, but in sales) with recent PS3, Xbox 360 and Wii releases, so the Genesis ports are an obvious choice.
Sonic & Knuckles goes the extra step of trying to actively market the other three Sonic games, as it acts as an expansion pack for Sonic the Hedgehog, Sonic 2 and Sonic 3.
Shacknews explains:
Buying each of the previous games unlocks the following:
Sonic the Hedgehog: Unlocks the game “Blue Sphere,” the bonus/Chaos Emerald level from Sonic the Hedgehog 3
Sonic the Hedgehog 2: Lets you play as Knuckles, complete with the ability to get to previously inaccessible areas of the game, and new power-ups added for playingas Knuckles
Sonic the Hedgehog 3: Play as Knuckles in Sonic 3, and also changes the flow of the game and connects it directly to Sonic & Knuckles, so that you can play the two seamlessly!
How prescient! Sure, today we have easy-to-download DLC, but who would have thought Sega would have an old IP that would actively market the idea of DLC in such an easy and still-innovative way Any other IPs in mind?