The pay-what-you-like offer provides five PC games from independent studios, with consumers deciding how much goes towards the developers and good causes.
Games include Frozen Synapse, Oddworld: Munch's Oddysee, Serious Sam: Double DD, New Star Soccer and Explodemon.
Frozen Synapse, New Star Soccer and Explodemon will be DRM (digital rights management)-free, while Serious Sam: Double DD will be playable through Steam.
The promotion will support GamesAid, a UK-based charity that helps children and young people in the UK.
"This is a great initiative for GamesAid and I would like to say a massive thanks to the indie developers who have kindly put their games into littleBIGbunch," said GamesAid trustee Ian Livingstone OBE.
GamesAid co-founder and Football Manager developer Miles Jacobson OBE added: "GamesAid is a uniquely democratic charity and this method of making these great games available follows those values. Hats off to Get Games and the devs for making this happen!"
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View trailers for each game are below: