They take a bigger share than epic for one: https://www.unrealengine.com/en-US/blog/announcing-the-epic-games-store
Also they recently announced a new policy that would favour big producers, which made a lot of indie dev unhappy: https://kotaku.com/indie-developers-dont-like-steams-new-revenue-sharing-p-1830830493
Well it does have dynamic lighting that reacts to changes in the environment. Despite the retro 8-bit style, the game can actually get quite graphically complex (for a 2D platformer). You're right that it could be made in flash! That version has much simpler lighting...
Why don't you just record it from your game? Audacity can help you with that.
That said, I'm pretty sure all sound assets in Super Meat Boy are copyrighted so if you plan on releasing/distributing your game you may want to think twice about using it, or at least get permission.
Joking aside it does seem like a fun game. I must say I'm struggling to play with touch controls because it's just not the same as physical buttons.
For those that wanna check it they have made multiple games using "mad dex" name. But it is strongly inspired by original SMB although the character looks a bit like Forever characters.
https://play.google.com/store/apps/details?id=game.maddex.action
I think they have something similar at the Meat forums.
My highest ranking was 16th, but it was really just a fluke on that level. I think my highest legitimate ranking is around 190 or so.