Although I already made a post for Micromania in France regarding their preorder page, that was a while ago and did not include something new from the bonus. Now that we know what the other keychain/keyring looks like (Crash Bandicoot), here are some of the stuff that Micromania is offering with preorders via their store page:
For the first buyers of Crash Bandicoot N.Sane Trilogy, receive a free key ring and digital bonuses exclusively from Micromania! Receive a key ring, a PS4 theme and exclusive avatars. Offer valid for first-time buyers while stocks last available on Micromania.fr.