Mages of Mystralia

You can do this near the start of the game. By the time you get to the Mystralia Castle, either by getting there through story or going there early from just exploring, you can get this.
All you have to do is use your ice creo on the river/ocean, stay on the ice bits over the water, just make a new one with the old one is starting to disappear. It's easier to get when you have the Runes: Time since it lasts longer before it fails and Size since it makes the platforms larger and extends them further.

Edit (thanks to JohnnieMonkey): seems you can get this without being over water, you can apparently do it over land too. I still suggest the same runes simply so you don't step off the ice by accident.

you can get this before you enter lava grotto just use creo, earth master and move and have alot of mana would be good too just cast the spell whenever you seeing your spell start to wear off and 2 mins later you should have the achievement