Tip: When determining a time limit, remember that players won't be as familiar with the level as you are. If you normally complete the level with around 100s left on the timer, others might run out of time on their first try.
I spent many years making games for sites that didn't require any coding knowledge, which I guess now was just a waste of time. Anyways, the one good thing that came from this was my ability to design some pretty neat levels. I'm hoping to apply this skill to my hacks, which i think won't be too hard because one of these creator sites was pouetpu-games.com, a website which was basically lunar magic in your browser, except you could only make and publish a single level at a time to the community. If you'd like to see some of these works, PM me.