It's interesting... First look and the example todo app are pretty easily understood... I'm still not sure how I feel about decorators defining UI integrations, though it appears at least at first glance much better than say Angular's approach. It's been a while since I looked at Vue, so don't recall it well enough to draw comparisons there.
Generally speaking, however, I've been really happy with the react-style component approach, especially with hooks and functional components. I've taken to using more of an MVC style approach with a controller to handle events and generate actions, then passing state change actions to a reducer (redux). It's not quite the prescriptive approach, but has made state very testable.
All of that said, it's nice to see new approaches... I'm curious how the yaml front matter in the .mahal files plays into things, since I didn't try running the application, but if it integrates with some sort of in-browser tooling extension, that could be very cool.