The best way to pop the balloons in less than 5 seconds is to memorise the 12 steps and press those keys as quick as you can. I found it easier to memorise the 12 steps after dividing them in 4 groups and instead of Up + Left ⬆⬅ and Up + Right ⬆➡, I pressed Up + Up ⬆⬆ which is quicker and also pops the balloons.
You'll need a few tries but you'll get it eventually.
Left ⬅
Right ➡
Down ⬇
Left ⬅
Up + Left ⬆⬅ (or Up + Up ⬆⬆)
Down ⬇
Right ➡
Up + Right ⬆➡ (or Up + Up ⬆⬆)
Left ⬅
Down ⬇
Right ➡
Up + Up ⬆⬆
To redo the tutorial, start a game, press 'Esc' or die, then click "(Re)start with tutorial".