The discussion so far is pointing directly at "5e with a new coat of paint." Abilities the same, ACs, DCs, saving throws, proficiency bonus. You're on well-traveled ground, to put it mildly.
As an example of steering away from another 5e, take a look at my
Core Rules Module (click) here. Once you're over the irony of the use of the "Core Rules" choice of words, you might find:
- Rule Zero. Yeah, so far, so D&D. Or any RPG.
- Rule One, campaign theme. Typical RPG, but D&D sort of imposes its own theme.
- Rule Two. The GM rolls a d20 too? There's a D&Diversion.
- Rule Three. There's no Succeed or Fail. NOW we're diverging from a lot of RPGs, not just D&D.
There are many more diversions in the next 80 or so rules. But my point is that not making another 5e starts at ground level. Using 2d10 to resolve conflicts is cool, but it will take a bit more to break out of The Shadow Of The World's Greatest Role-Playing Game.