Got a code for buying some games from the current sale.....for Sim City 2000....I already own it...but as the email says, I should be able to gift it, at least. But, the page seemingly has no way for me to complete redemption.

Better yet would be if GoG might give us redemption codes for games we don't already own? Guess that might be asking too much:)

You should be able to click on the "progress bar" for the free games on the main gog homepage. The codes you have earned so far should be underneath the game. Just give that code to whoever you want to get the game.

Also the free games are giving you codes even if you don't own it. For instance I didn't own sim city 2000 and I got a code, which I redeemed myself for the game. Hope that helps.

Edit: A moment to slow, dang ninjas :)

^This. Just give it to a friend or find someone to trade you for it.

Since you already have Sim you cannot redeem it anymore. Just give it to one who dont have it.