Sega is launching a range of classic games to play on iOS and Android. They’ll be free to play with ads, or $1.99 ad-free.

While the Sega Forever games will be a mix of straight ports and emulation, they’ll also have some more contemporary features such as game saves, an online high score leaderboard, and support for wireless Bluetooth controllers. Sega says the games will be faithful to the originals, but have adaptation for mobile devices (and presumably for touchscreens.)

The initial releases, coming tomorrow, are Altered Beast, Comix Zone, Kid Chameleon, Phantasy Star II and Sonic the Hedgehog, with plans for a new batch of releases every two weeks. The titles will straddle consoles from the Master System to the Dreamcast.

Once downloaded, the games can be played offline. The only in-app purchases will be to remove ads. While that fee will initially be $1.99 per game, eventually there’ll be an option to pay a monthly subscription to remove ads from all games. That means Sega will have to get the balance just right of making the ads intrusive enough that some people will pay to remove them, but not intrusive enough to create ill will and bad reviews.

Sega’s Mike Evans, the man behind the project, says there’ll be some titles that were previously only released in Japan, including Segagaga, something of a metagame spoofing the Dreamcast-PS2 rivalry.