Tell the Time teaches the first two things a child needs to read on a clock with hands: o'clock and half past.
What your child is learning
A clock face asks a lot. There are two hands that mean different things, numbers that stand for hours when the short hand points to them and for something else when the long hand does, and a circle that has to be read clockwise. This game keeps to the two simplest positions so that the idea can settle.
At o'clock, the long hand points straight up to twelve, and the short hand points at the hour. At half past, the long hand points straight down to six, and the short hand sits halfway between two numbers.
How to help
Start with the long hand. Ask, "Is the long blue hand pointing up or down?" Up means o'clock. Down means half past.
Then find the short hand. For o'clock, read the number it points to. For half past, it has gone past one number and not yet reached the next. The hour is the one it has passed. This is the step children find hardest, so take your time over it.
Use the colours. In this game the hour hand is always yellow and the minute hand is always blue.
One of the wrong answers always swaps o'clock and half past for the same hour. If your child picks it, they have read the hour correctly and need to look again at the long hand.
Taking it further
Find a real clock with hands and check it at mealtimes and bedtime. "It is half past seven. Time for a story."
Quarter past and quarter to can wait. For HTML5 games about time, getting these two right first is what matters.