Dark Matter on Steam. 80% positive of 21 user reviews. 18 users have this game to trade, 4 want it, and 173 own it in library. In 13 bundles and 0 giveaways.
You could try asking the publisher Meridian4 for a replacement key, though I doubt they'll do anything.
Not sure what the best way to contact them would be. Maybe via Twitter DM?
Meanwhile, it's up to you whether to give @cprn's giveaway a negative feedback (because the key didn't work) or a positive feedback (because it wasn't really their fault). Or, perhaps Cprn would be willing to offer an alternative game for you?
Hey. Yeah, there are no typos and it's a Steam key. I'm giving away old keys from Fanatical instead of trading, because they often turn out to be revoked. Sorry. Just leave negative feedback.
[edit] Sorry for delay, but I didn't know there's a whole forum attached to IG GAs – I have no notifications or anything, just got here on accident by randomly clicking to find an option.