Just a random idea:- why don't you put ads on scirra arcade and make it like other gaming sites? I mean just launch a online html gaming site like poki,gamedistribution etc. And you already have scirra arcade.
It would be win-win for both sides. Scirra will earn a good amount of money and this will go back in engine development. On developers side, there will be a safe and non-scammy option to upload games and earn money in web domain