The idea of not wanting to collect too many coins and having tons of coins in a level can bring in a nice challenge. However this game's biggest challenge is the fact that the controls are really, really floaty. The camera nudging between left and right whenever you turn around is really disorienting and can make some people nauseous when playing the game. Judging by the 10 year gap between this and the last game you made, you must have not spent enough time figuring out good physics in video games.