Still no way to check keys?

I believe so. I got A Valley Without Wind from one of their things today, and I don't know if GMG uses all the same or how they distribute mystery keys.

In theory, you could find someone with enough games in their library and have them check, but obviously if they don't have the game it would activate and you would be out the key, and of course then they have the key so you'd have to trust them not to use it themselves.

No there's still no way to check, but don't get your hopes high like I was, because I received two Hacker Evolution from them

View attached image.

Brute force. That's why keys checking system is not exists.

Turns out the key was for A Valley Without Wind 1 & 2, for the curious. I let the friend I was giving it to think it would be Sakura Angels. He made many sad faces. :D

I got some racing game from them when buying ESO. Also I don't think you could bro.

1. Build a keygen
2. Build a bot which automatically verifies generated keys with the "key checker"
3. ?????
4. Profit

And that's why a "key checker" isn't a thing yet and probably never will be. :P

I still have my keys from their 0.5Ł bundles (2 different one) and because they just dumped them to my account, I can't even differentiate them - It has for example games I own, games I don't own and want, and games I don't own and don't want, so activating each of them does no good at all... yay for GMG's service, really quality one.