This tutorial explains how to add a timer to your game.
For this tutorial, we'll start with a sprite following the mouse, and coins moving to random locations after colliding with the sprite. A picture of the blocks is below.
From the timer drawer, get the "start timer" block and drag it under the "when game starts" block.
Now we'll want the label to show the timer's time. Drag the set label text block inside of the forever loop.
Replace the "hello" block with the "timer's time" block from the timer drawer.
The timer should count up, but it stops at 5, and it has many numbers after the decimal. We'll fix both issues.