Thank you for trying it out! I’m always a big fan of the retro sci-fi aesthetic, and I’m glad to hear others enjoy it too.
Regarding the F5 issue, pressing it will just prompt a browser refresh, so the page is actually reloading instead of crashing! You do actually raise a good concern that I haven’t considered; F4 may be a bit cumbersome on some keyboard layouts. It’s an engine hard-coded key for fullscreen, but I think I can change it for the upcoming version, I’ll look into it.
Thanks for letting me know!