I think these kinds of templates are super important for developers, so thanks for making this! I might open it up this weekend and try to make something fun. If I do so, I'll also play with some plug-ins and report back on what functions correctly with this! GALV stuff is the best, and I use a lot too, so I'm sure there's some great opportunities.
Also, the title says "Sidecroller", which I assume is a typo. :)