I had a lot of trouble with trying to not use any plugins. I wanted to try to avoid using plugins for this jam, since that is basically what I've always done with these jams.
Unfortunately, the game is very limited in what it can do without plugins, but I think I did pretty well with pushing the engine to do stuff it wasn't really meant to.
It definitely sounds like the free version was very buggy. I was using the steam version, so I didn't have the same issues, though I think they updated the engine in the middle (July 4th) and I, like a crazy person, despite the update having no benefits for my project (seeing as how I wasn't using plugins), updated the core script... and broke half my game.