LONE WOLF: Horizon was once known as Lost World Zero, and it looks like it's a game that was abandoned in Early Access. It's the (solo) project of a high school student, since graduated, and he has been honest about his unrealistic expectations with the game, and with his current lack of plans to revisit and finish the project. Just so you know. The game is no longer for sale on Steam, but there is still a store page.

Since we're in the wilds of 2020 and keys are not as eternal as we once thought they were, I also need to say this:

This key is an old key. It was purchased several years ago. To the best of my knowledge, it's as fresh as it was the day it was bundle-bought. I haven't used it, and I haven't given it away. However, many indie developers revoke unused keys these days for no reason, so it's not possible to rely on keys the way we did once.

If the key doesn't work, please contact me. If I can fix the issue I certainly will.