I have been getting pretty much comfortable blogging about the various crypto NFT games out there. I am sure you must have read my Karastar review. If not do that I am sure you would find one good game worth playing for free and mint the crypto along the way. While you wait for Chimera to get mainnet release, you can setup your karastar account.
Chimera is new and like splinterlands it has it's companion and summoner type relationship in it. The game is also in a beta so I suggest you to just put on your email into their funnel and wait for "go" message for you to play the game. In near future I suppose they may open up for all and will help get into the chimera universe.
How does Chimera works?
If you read about chrimera from official source, you'd understand that it works similar to the splinterlands. Like chimera has the chosen ones along with the chimera for the gameplay. Splinterlands has the summoners and the monster for the game.
Chimera seems to be pretty generous to open up with the NFT airdrop as you can see from the giveaway. It however means that it would get a bit resource burner inside the game. The game claims it would remain free to enter and play to earn game. However such games are not easy to sustain unless they make sales in some way.

For now you can connect the wallet and set things up, but I am afraid that would be also still buggy to be honest.
It's too early to say anything about their ecosystem and the gameplay as it's just close to mainnet release and we don't even have the beta access as of yet for any strong review.