I really like the artstyle and design choices you made. The game idea is good, too. But I think the first minigame is to monotone. I didn't had the patience to collect 300 coins, to get to the next minigame. maybe add some coins which are worth 2 or 3 but are faster? This, combined with some Bugs which made me restart the game, made me quit after a few minutes of gameplay.
Don't get me wrong. There is so much potential in this game, and if you want to continue working on this, I'd totally check this out again!
Keep it up! :)