Sigi - A Fart for Melusina

You'll get very close to this by completing the game. I had approx 2300 when I did my 1st run (there's no in game counter and the tracker doesn't count either, it's an estimate based on how many times I had to do the below)

I did the 100% achievement 1st, and didn't pick up every coin along the way either as 100 coins gives an extra life and they seem pretty abundant anyway.

So if you get to the end beat and don't have enough coins, when the boss is defeated and you're returned to the main menu there's a continue option. Simply replay the 1st level over and over until it pops, there's approx 80 coins in the level and it takes about 30 secs. I only had to do 2.5 runs of this level and it popped in game.

I'd suggest against farming this early if you're going for the 100% get everything in one run achievement as you want to focus on the time. Although it's not difficult.

By Skate 323 - For some reason once I beat the game I didn't have a continue option. I had to select new game but then after playing level 1 two times the achievement unlocked.