Steam's new Sega Mega Drive Classics Hub only launched yesterday, but modders are already having their fun with it.
The hub ads Steam Workshop support to all Mega Drive games on Valve's platform. This lets you share and download mods for those games.
And what mods are already available! The most popular, at the time of publication, is this beauty:
Check it out in the video below. It does exactly what it says on the tin.
There are more... useful mods available, such as Sonic 3 Complete. This improves the base game with bugfixes and adds optional music based on the original PC version.
And here's a cool one: Knuckles in Sonic 1. As you'd expect, it lets you play as Knuckles in Sonic 1.
There are a lot of other cool mods already available, many of which focus on making classic Sega games better in some way. Alien Soldier Original 60hz Japanese Version, for example, replaces the 50hz-optimized European version of Alien Soldier with "the only version people should be playing".
Sega hasn't released mod tools. What's happened here - and this comes as something of a surprise - is Sega has allowed anyone who owns a classic Sega game on Steam to use Steam Workshop to upload and play ROM hacks.
"Steam Workshop functionality is a platform to share the wealth of custom Mega Drive & Genesis ROMs out there and support the highly talented and engaged community of modders behind them," said community manager Daniel Sheridan on the Sega blog.
"Now content creators can easily share their custom ROMs with other Mega Drive & Genesis fans giving a new perspective on so many beloved retro titles."
In short, go ahead and go!