Shovel Knight: Treasure Trove

For this achievement, I actually got it without trying on Forest of Phasing. First, you will need the Phase Locket. It can be acquired on the Lich Yard level, although I bought it after having completed the level from Chester. Just make sure you have it.

While on the Forest of Phasing, there is quite a bit of gold already lying on the spikes or that you can drop down on spikes and collect. This will get you most of the way to the 2000 required. However, I died a couple times during the level on spikes as I learned the mechanics of the relic. What I found is that collecting my own gold over again by jumping from the spikes to the winged gold also appeared to count. I eventually got the achievement from collecting my own gold over again.