Step 1: Go into any battle.
Step 2: Place whatever units you want. Boost them, whatever.
Step 3: Turn the speed up to x4.
Step 4: Place a Healer.
Step 5: Sell the Healer, don't click anything.
Has the game sped up? If so, how much? x1.5? x2?
Step 6: Click on any character, or bring the character menu up in any any way.
Has the game slowed back down?