Watch out with those Threads!

I added a basic loader scene that took care of getting everything ready first. But, it turns out that this locked the HTML5 version up because it uses a Thread (extra process) so we can see visual progress. Thankfully, OS.get_name() kept the loader working on both cases.

I know that (most) players would rather if I focused on adding more Hearts but it's important to have a solid foundation first.