To celebrate the fact that it's been two decades since Sonic first graced our screens, Sega has released a Sonic 20th Anniversary companion iPhone app.

Along with access to the Blue Blur's latest news and a bunch of downloadable wallpapers, the app offers two playable games.

The first of these, Sonic the Sketchhog, is a Canabalt-alike title that challenges you with avoiding enemies, pits, and other hazards.

The second game is a special Lite edition of Sonic The Hedgehog 4, Episode 1, which we gave an impressive 4/5 at review.

And just so you know, this short trial version isn't currently available anywhere else on the App Store.

Sonic 20th Anniversary is a free title, so you might as well go and grab it.