The only way now is to report spam comments , every 1 reported correctly=1sg. You can search for the main forum page about spam by the moderators for more details.
Also, if you do it for level experience, then there will be a gem reward if you level up
I believe this is the thread that mentions the spam comment reporting, written by the mods:
https://gamehag.com/forum/t/53175-earn-soul-gems-from-reporting-spam-comments
in 3 steps
Choose the game that interests you and play itfor free.
Every game has some quests for which you will receive Soul Gems.
You can exchange your Soul Gems for Steam Wallet top-ups, game keys, CS:GO Skins and other rewards.
You know that on Gamehag you can get real rewards for free, right? Join us, complete walkthrough and get your chest!
What I need to get gems from forums