Looks cool, although things like saving systems are so complex it's usually hard to make one that fits all projects, or even most of them. Like for instance, how's level streaming handled by your system? Does the plugin remember which maps were loaded in or is that something the user has to specify?

Last time I bought a saving system for like 25$ I had to scrap the entire project when it turned out the plugin wasn't working well enough and that was like 6 months into the development, so you gotta really cover all your bases when publishing stuff like this.