My question is can I license my Game project with GPLv3 and have my name right of the copyright notice even if I am below 18?
The only issue relevant to your age is the (ir)revocability of the license. GPLv3 purports to be an irrevocable license. To be really irrevocable, the license would need to grant certain rights in exchange for something of value, that is, you need a license that passes muster as a contract. Copyright licenses are typically treated as contracts, but it is not clearly established in law that licenses are contracts or are not contracts. Out of the goodness of your heart, you can grant permission to use your property, but you can also withdraw that permission. If you have a contract granting perpetual permission to use your property in exchange for something of value, then you can't later withdraw that permission. In the case of Jacobsen v. Kratzer, the sides advances opposing theories that the license was a "bare license" vs. was a contract. (The matter was ultimately settled out of court). This article puts together the legal factors surrounding the notion of license as contract, see p. 21 ff, and esp. §IV for arguments that licenses should be contracts, to be fully enforceable.
A contract for non-essentials formed with a minor is not enforceable, until you are 18. You could therefore revoke the license, until you are 18. Anyone who uses the software does so at their peril. However, if the license is not a contract, no existing legal doctrine (in the US) whereby the permission is irrevocable. In other words, yes you can, at their peril.
The whole license-as-contract issue is very complicated, and I'm only focusing on the revocability issue. There is a separate question whether one can sue a user for both copyright infringement and breach of contract. The case of Artifex v. Hancom, see also this analysis, found that (in the particular case), plaintiff can pursue the matter as both infringement and contract breach.
If you wrote the software, and you were not employed to write or similar circumstances, then you are the copyright holder. And as the copyright holder, you can license the software under any license you wish, including a GPL license. There's no problem here for you.
The problem for others is that as a minor, if you entered a contract then either you or your guardian(s), usually parents, could void the contract, until you are 18. It's not clear to me what exactly the legal consequences would be if you or your parents decide to retract the licensing terms. So if I knew you were 17, I would probably not use your software if I can't afford the risk of losing my license.