How do I Make a game harder as time progresses

Hello All!!!!

I've been playing with construct for a while now however i have never made a sort of endless runner type of game just without the running part.

basically its a game that spawns cats and its your job to remove the cats.

The question i have is, How can I have the game summon more cats as time progresses making the game progressively harder?

like 0-60 seconds maybe spawn a cat once every 10 seconds at location A B or C

60-120 seconds maybe spawn a cat every 5 seconds or maybe 2 cats every 10 seconds. etc etc etc

Simple way to achieve that could be this.

make global variable Difficulty = 1,

Every 60 seconds:

Add +1 to Difficulty

Every 20/Difficulty seconds:

Create object Cat

This will make it so that for the first minute it spawns cat every 20 seconds.

Second minute it spawns cat every 10 seconds.

Third minute every 6.66 seconds

etc...

Simple way to achieve that could be this.

make global variable Difficulty = 1,

Every 60 seconds:

Add +1 to Difficulty

Every 20/Difficulty seconds:

Create object Cat

This will make it so that for the first minute it spawns cat every 20 seconds.

Second minute it spawns cat every 10 seconds.

Third minute every 6.66 seconds

etc...

Aw man you make it sound so simple! i guess i just needed an extra head to break it down. Thanks! ill give it a try!

You could also do the same time of thing based on score, if you prefer it get harder based on that instead of time.