Between
On a single interval, people often tap a little early. The midpoint is a moment, not a feeling of ‘about now’. The flashes are the whole cue: the game is playable with the sound off, and the timing does not change if you mute it.
Look at the two flashes. On the real try, tap once at the midpoint. This is a tap, not a hold.
The scoring formula for Between is published on How to play, and the constants there are still initial values.