A word or succinct phrase for "capable of producing financial income"

Moneymaker: something that produces or yields much pecuniary profit.

Revenue generator: A revenue generator facilitates revenue generation.

If you are looking for something that means "able to produce enough money to survive", I would recommend sustainable, and if you want to make it more clear, economically sustainable.

Credit to @bib for putting it in the comments first, but the succinct and non-jargon way of saying that you expect people to pay for the game is:

The game will be:

• For profit.

As opposed to "Freemium" or "Free-to-Play", people will be expected to pay for the game. Profitable is another way of phrasing this, but it carries with it the assumption of preordination. (I.E. that the game will make money, rather than expected to make money.)

I don't like monetizeable because of the weasel-word jargon — unless it truly is expected to make money through another means besides user-pay. (Pay-to-play "freemium" models, advertising, click-throughs etc.) I don't like revenue generator and moneymaker for similar reasons: they have odd connotations.

I'd suggest earner. Or to be more specific, perhaps wage earner or income earner

Monetizable is a great word, quite often used to mean "convertible into monetary units." For example, "increased flow through an intersection is a benefit that is not just a convenience but is monetizable, as well."

I wish there was a word coined from dividend “dividential” to express something that is capable of producing both financial and social benefits.