A Swirly Portal
Swirly Portals are flat spherical circles that radiate pulses. They are found at the end of each level. In order to complete a level, a Unit must first land or pass by one. They only appear in Mech Mice Tactics.
When stepping on one of them, the End Screen will appear, showing how many Treasure Tokens you have collected, enemies you have defeated and amount of turns you have taken. There is also a button to progress you to the next level or go back to the Select Screen.