Sonic latest iPhone/iPad outing, an endless runner game titled Sonic Dash, is now free to download.
The game was originally released March 7 at the price of $1.99. That paywall has been removed in favour of in-app purchases which offer Rings and other in-game currency in exchange for varying amounts of money from $0.99 to $28.99.
A spiritual follow-up to Sonic Jump, Sonic Dash was developed by at Hardlight Studios and sees players run into the screen through 3D environments, dodging obstacles and enemies and collecting rings.
A recent update - version 1.1.0 - was released on March 29 and added new Daily Challenges, which players can complete to unlock 'prizes' including Red Star Rings and additional characters.
It's compatible with iPhone 4 and newer, iPod Touch 4th-gen and newer, iPad 2 and newer and iPad Mini. It has been optimised for iPhone 5's wider screen.