A completely new Mega Man series with no angsty Zero nonsense, art style like the classic series, gameplay like the X series and the Zero series injected into a 3rd person action RPG. 40+ hours of content, dozens of bosses, weapons, armor upgrades.
No making the mistake of doing voiceovers which you can't get the license for later. No bullshit fetch quests - if you can't make a sandboxy open world game without putting in fetch quests, don't make it open world; zones with creative, unique concepts are better than having a big open space you can't figure out what to do with other than throwing around random repetitive enemies and collect-a-thons.
Add a level editor, a boss editor, and a weapon editor, and make the only online component of the game be being able to share zones you create with other players.
Sorry, I know I'm doing it wrong and that's way more text than you were looking for, but if one day I read that this game was in production, I'd yell out loud.