Emphasis mine. Sounds like they're not ruling it out.
For people who'd like to support the project, get rid of the few ads and possibly also some other extra-features such as in-game avatar wearables or similar, there could be a subscription option as well.
Interested to hear what the options you were thinking of were? Nothing is yet implemented on that regard so this is a good time to influence the outcome :D
Personally, I think as long as the price is right, and you include some screenshots/trailers, most people wouldn't mind this model - particularly if you're able to choose your games, which I think would be a huge plus
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Another monetization model idea: a simple subscription model
Free users get X plays a month (5-10) - this means anyone can play it, probably for 1 or 2 nights, before they have to upgrade.
Subscribed users get unlimited plays - with some small perks like avatar customization or something. You could also experiment with other things like including new games in the subscription for the first few months they're released