So I've been reading MS Paint Adventures. It's almost over (it's going into its epilogue now) and I quite enjoyed the ride. This is a bit of fanart I did, from a strange encounter early in the plot of Problem Sleuth in which the titular character drops an important item through his window by accident, then later picks up the window (!) and tries to dump his items back out. (The window was later revealed to be a portal showing a view from an alternate universe, which is why it was able to be moved in the first place). ?The results of shaking the window up and down revealed this: It appears to run on etch-a-sketch technology.
MS Paint Adventures is a weird comic and/or a messed-up game, depending on how you look at it. It's a comic, done in the style of an old adventure game, created as a collaborative effort in which the main character's actions were based directly from the readers' suggestions and queries. The fourth wall is rarely broken except to poke fun at the readers and some of the really dumb suggestions.
I'd guess the whole thing falls under PG-13 for occasional mild swearing and innuendo. But I'm not sure how mature a cartoon has to be rated to have swear words in it.