Here is an email I got about one of my android games today:
Hi,
I want to make a deal with you. I'm ready to pay $500-$1000 for the source code of this application (named in email subject). Note that I'm planning to publish it as is after adding Arabic labels.
You still have the right to keep your copy published if you like, after you sell the game code and resources.
Regards,
I don't know what to think about this.
He's saying he wants to publish a localized version of your game, for which he's willing to pay you a flat fee. It's a rather non-standard way of positioning the deal, though.
I imagine you'd want to maintain ownership of your source code, so you could ask him if he's agreeable to a limited license (under which he can use your source code only for the purposes of localizing your game).
I imagine you'd want to retain your copyright and trademark, so those would not be part of what's being sold.
You should think about whether or not the price is acceptable. If a thousand dollars isn't enough, you can tell him you want more. Or you could even ask for some sort of royalty (in which case he would have to tell you about his business model, and he would have to incur the added expense of royalty administration, so might want to pay less up front).
I imagine he'd want your help in localizing the game. The cost for your time in doing that could be part of what you ask.
I think you'd also need to know how he's going to use the game. You don't want to get in trouble with your government, if this guy might use your game to promote or train or teach in a way that might be antithetical to your government's interests. So you could put a clause about that in the agreement.
And there should be a clause that he's not permitted to sublicense the game without your permission. And you'd want to know every location where he publishes your game.