Enemy portals

Is there a way to make an enemy portal appear onscreen with a random enemy spawning from it.

Yes, there are some ways of doing this. It would be good to know more details about what you're trying to achieve, so we can help you better.

One way, for instance, is to create the portal at a random position (random(WindowWidth), random(WindowHeight)) and, then, having it spawn a random enemy from a family.

Cheers.

you can spawn random enemies quite easily just have a variable that is at 0 originally then when you want the enemy to spawn set the value of the variable to for example to

Random(1,5) then if it is equal or bigger than one but smaller than two spawn enemy 1 if it is bigger or equal to 2 but smaller than 3 spawn enemy three etc.

Here's an example: https://www.dropbox.com/s/o73of1g3uqc4y ... .capx?dl=1

Hope this helps. Cheers!