Sega is making some of the most beloved games of the 1990s totally free to play for the current generation of gamers with their new “Sega Forever” service, available on iOS and Android. It makes “nearly every Sega game” available for free, from the era of the Master System all the way through the Dreamcast.

The first round of games available includes Sonic the Hedgehog, Phantasy Star 2, Altered Beast, Kid Chameleon, and Comix Zone. The hitch here is that the games include ads, though players can pay a $1.99 fee to get around them, per game. Games will be released biweekly.