How do you make a level style game without using too many events?
Section 1
First make a Test level, then (at least) one more level. Now make an event sheet title something along the lines of 'Level event sheet'. You'll use this for every level.
Section 2
Then, you add every ability,control, and anything of the like to this one event sheet. Specifically, once you make an ability(ies) that only applies to certain levels. Simply add the condition System > Compare two values > Top: LayoutName equal to Bottom: Layout EXAMPLE You can also invert that for unlockables and not exclusives and just say NOT System > Compare two values > Top: LayoutName equal to Bottom: Layout EXAMPLE.
Section 3
Finally simply go to every level layout and click on it then change the event sheet to this one.