I finally managed to lock down on an idea.

So basically, you are an alien whose job is to clean the earth of trash. The more trash you have the less human population. However, the less trash there is, more humans can live on the planet but in turn generate more trash.

The goal is to get as much trash cleaned from Earth, in 20 turns or so (haven't decided yet on the number).

It will be turn based, and each turn you have a number of action points to use abilities and upgrade points to upgrade those abilities.

Will be using p5.js for the canvas, and all the buttons and menus will be HTML. Was thinking whether I should use Angular.js and node.js as well.