Hi, thanks for your feedback!
About the size: yes it's a bit heavy, sorry about that. I can't say we really invested in optimizing size on disk (two days was short!). But that's definitely a valid feedback for future - longer - projects.
The only online feature we have is the leaderboards. It is just sending your high score to a server. We've used the amazing Leaderboard Creator from Danial Jumagaliyev (https://danqzq.itch.io/leaderboard-creator).