Tuning physics values has no definitive answer, there is only one way -afaik- around it: Trial and Error.
My suggestion is that you add a punch of Sliders/TextInputs in the game, and each one would change a parameter (Max speed, Gravity, ...etc).
Then you play around with them until you get a sense of how each one affects the player.
It would help if you have some references from SMB, for example:
- Simple jump: when you press jump, how high does the MeatBoy jump? Then try to replicate that in your game.
- Jump forward.
- Wall jump.
- ...etc
Try to mimic SMB behaviors one-by-one, and hopefully it will all work out in the end!
Good luck!