The animation idea is a great point: do you have any suggestions on how we could approach that?
Presumably look at the order of operations, maybe move collision detection after the scene drawing. I have no idea what your code looks like, so can’t help more, sorry.
where would you recommend a progress bar?
When I click “Run game”, I see empty screen for a few seconds before the game fully loads. Look at many other web games here, many have a loading bar on that screen.