I'm extremely interested in this tool as I've always been a big fan of pick up and build kind of engines. So would it be possible to make a game that you can then in turn sell?
I was asked this question a couple of times already, and my current opinion on this is no, sorry.
Pocket platformer makes it really easy to make a game, as the physics, data handling etc. is already done. The task of users is to "only" make game, which in relation to what i did for the tool is lower. I don't want to generalize this topic and i'm not saying it's your case of course, but some people who have asked me this, were just trying to make a quick buck, by using a lot of default assets and not putting a lot of effort into the game. I made this tool free for people to have fun, and put a lot of work into it, and people using my work to make money sounds unfair to me tbh.
I would highly advise to make games with the tool for the sake of making games and be creative instead of trying to make money. Espcially as i think that pocket platformer games wouldn't sell well, and would just lower the player-base a lot, by creating a pay-wall.
As for whether or not games would sell, I think there is potential. I had one person comment one one of my game jam entries that if I produced a longer version of the game, it is something they would pay for.
Also, you should include a "Donate" button to Pocket Platformer. I haven't made money yet, but if I ever did, I'd want to contribute back to your efforts.