Hello,
This is so mesmerising, I can see why you've found it an interesting project!
A few things.
First, there's a particle in the top left on loading the game. Others have mentioned it too. Perhaps it's only here for the web version?
Second, dark matter resets seem to top out at around 1 trillion and I don't seem to be able to go higher. Again, is this a limitation of the web version?
Autosave hasn't worked for me. I have the 'no saving on mobile' warning on my laptop, which means you're not identifying the user's device.
Finally, the dark matter upgrades and reset button are black on a charcoal background. It took me an hour to realise they weren't simply more text but that I was able to (and should!) interact with them. Please consider giving them a different colour or outline feature for visibility?
Well done, this is very fun :)