You need to register both on gaming.lenovo.com/game-key-drops to get the code and on us.gamesplanet.com to use the code and get a steam key. Boring but doable...
game on steam: https://store.steampowered.com/app/1472560/I_Am_Fish/
Lenovo has different pages apparently, not sure why...
To be sure to login in the right one. Go to the link, wait 10 min to activate the giveaway then login/sing up from that page. The code can be used on gamesplanet to get a key.<<<
next game:
I couldn't even claim it. I waited in the queue, created a lenovo account, confirmed my email, "claimed" the game, logged into games planet with the lenovo account, tried to get the Steam key, was told to enter my email (again?), but apparently it now refuses to accept my email. I actually can't be bothered to continue!
There seems to be different lenovo pages, help yourself with the browser and find the page "I am the fish: giveaway code" once inside use the code on gamesplanet to get the key