Ground Pound is when you need to get down to the ground quickly while midair. Obviously, you can perform this move midair. You can perform this move by holding shift or any sprint button, midair, in which it will rapidly bring you down. When you land, depending on high you were, it will create a force around where you land.

Tagging is using the collectables around you and sprinting past them; price to pay for leaving things behind basically. To perform this, just sprint by next to a collectable (crystal, coin, or any item) without picking it up. This gives you a speed boost.

Blink Dashing is basically going forward. Is it teleportation? I don't know, but I do know it does let you phase through walls. When you perform it, a orange-like sphere appears, and it is going to be where you can go forward. It will change depending if there is an obstacle in the way, but sometimes it does let you teleport through if it is shallow enough and you could either phase through the platform or just... find other secrets. To perform this, hold shift and space, or if you are on controller, hold down the top stick and the A button; sometimes pressing the top stick will do it.

There is a hidden move that is way harder than Blink Dash; Leaping. Its a matter of balancing inputs to achive this.

To do it, first key is the Space Bar and then Shift, don't do it at the same time, otherwise you will Blink Dash, but make sure you are on the ground, otherwise Ground Pound would happen.