With Relic's 25th Anniversary(store.steampowered.com), along with sales discounts on their games(store.steampowered.com), the Armor of Heroes mini-game is being offered for free to keep, but it must be redeemed by June 23rd (US timezone):
To redeem the game head to: community.companyofheroes.com(community.companyofheroes.com)
You will need to log in [or sign up] and then click the main banner to arrive at the rewards page
Link your steam account on the rewards page
Once you have linked your account, you will need to claim your copy
The button to claim is found where the previous link Steam account button was previously placed