Above post is correct.
1. .COM is the only choice. You are handing traffic away to the .COM if you get anything else and making it more valuable/expensive to buy later.
2. .IO is the only possible other choice, if available. Originally popular with tech/startups, since agar.io it has become a popular extension for games.
3. Unless the .NET and .ORG are available for $10 don't get them. If they are, get both, if you're happy to lose traffic to the .COM.
4. Don't consider any other extension other than .COM, .NET or .ORG even if they're free with a complimentary blow job.
5. $3k is not a bad price if it's a short one word .COM or the exact (one word) name of your game, but if not, or you just don't want to pay that, get "name of game"+game.com - ie, tetrisgame.com, which is far better than tetris.game or any other extension. Or get any decent freely available .COM for $10, which can be the name of your company/publisher and used if you develop more games.
In short: get a .COM.
Edit: I assumed this was for a game but if it's a games site (that lists or contains other people's games) it should be even easier to use any kind of name. Just call it something+arcade.com, or something+games.com - being .COM and memorable is what really matters.
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