Half a gig is pretty normal for a lot of RPG Maker games because of the, uh, whatever they call those files, the RTX or whatever being included.
That said, games with lots of TF and expansion tend to have absolutely inflated filesizes thanks to having to make 100 variations of the same scene to cater to the different sizes, shapes, clothes and accessories the character might be during that scene, so I expect it's gonna explode in size, it's only got 13 pictures right now, apparently, heh.