The player is Geralt of Rivia, a professional monster slayer, a witcher. Entangled in the political turmoil that engulfed Temeria, Geralt helped quell the rebellion of the Order of the Flaming Rose. Soon after, he saved King Foltest’s life when the monarch was attacked by a witcher-like assassin. He continues to protect the king, serving as his bodyguard as Foltest strives to bring peace to his kingdom. The Order’s last bastions have yielded to the royal army, yet one more task remains - the Baroness La Valette announced her secession from the realm, and her fortress must be taken. A month after the attempted assassination, Foltest’s armies stand at the gates of La Valette Castle, preparing for a final assault. Still at Foltest’s side, Geralt is among them, unable to begin his personal quest to discover the mysterious assassin’s origin and identity…
As the first commenter said, it's a GOG key, but here are the Steam reviews: 88% Very Positive, 88% on Metacritic
£2.24 is the same price as the recent Steam Winter sale, but I believe you can give 5% to 'My Wallet', so another 5% off (towards something else)? Also, if you've recently bought a Humble Monthly Bundle (XCOM 2), you 'Get 10% off Humble Store purchases' (so maybe buy XCOM 2 first if you haven't already?).
Also a GOG key:The Witcher: Enhanced Edition Director's Cut
for £1.04 (Steam reviews: 86% Very Positive, 86% Metacritic
Games with Steam Keys:Abzu
is £4.49 (Steam reviews: 92% Very Positive, 84% Metacritic
is £2.74 (try the demo on Steam reviews: 97% Overwhelmingly Positive, 86% Metacritic
is £9.49 (Steam reviews: 87% Very Positive, 84% Metacritic
for £10.49 (try the demo on Steam reviews: 95% Overwhelmingly Positive, 87% Metacritic
is £7.25 (Steam reviews: 97% Very positive, 81% Metacritic
GOG game deals have expired, Steam key deals continue for another week.