What other games have gone for 100% off in the past? Off the top of my head…

Dead Island Riptide
Half-Life 1
Hue
WarHammer 40K Gladius Relics of War
Battlestar Galactica Deadlock
100% Orange Juice
Metro Last Light Redux
Cryptark
Dungeon of the Endless
Endless Legend
Content Warning
Field of Glory 2
Intravenous
We Were Here Expeditions The Friendship

RPG maker XP
Desktop Dungeons
Castle Break
Cakey’s Twisted Bakery
Drawful 2
Machinika Museum
Space Crew: Legendary Edition

Wow that’s a lot more than I remember.