Visit the main Sale page for more details and get in on this limited-time only deal.
From the Sonic Generations PC Download product page:
The ultimate celebration of 20 Years of Sonic gaming, Sonic Generations delivers the definitive experience for Sonic fans new and old.
Sonic’s universe is thrown into chaos when a mysterious new power comes into force, creating ‘time holes’ which take Sonic and his friends back in time. Whilst there, Sonic runs into some very familiar characters from his past including a younger version of himself! Now they must team up to defeat their enemies, save their friends, and find out who is behind this diabolical deed.