How do I gradually increase the speed of falling objects?

Hi!, i'm making a "Falling from the sky" bubble game and trying to figure out how to make the bubbles increase speed either by every x amount of clicks on them, or by every x amount of seconds.

Have researched the forum and tried all the guidelines I can find on this topic without any success. I'm relatively new to the game programming thing so simple step by step explanations are heavily appreciated!

all you do is use timer to check the time for speed Increase example

1 Timer = 0

2 system add dt to time

3 if Timer - 20 then set max speed to whatever: Set Timer to 0

so every 20 seconds speed will be increasing