Fun game overall - I really liked the visuals, the minimalism executed really well and the game felt smooth. I had a bunch of close calls that felt really satisfying to narrowly avoid. A couple easy tweaks that I think are worth keeping in mind for the next one:
- Consider lowering the alpha a bit on the particle trails (or other visual effect to make them distinct); basically just some visual juice to add clarity, my eyes got used to it but at first it was hard to distinguish subconsciously between "this is a particle that will hurt me" and "this is a trail that i can move through".
- Make difficulty ramp faster/more, fewer max lives, more objectives to get. Maybe even dont make them respawn. I didn't get hit until 5 minutes and then realized "oh wow I still have another 7 lives." I get that difficulty scaling isn't always priority in a jam but figured I'd note my experience.
- I know you said it runs better in download than browser so I'm sure that's part of it but lag in audio started around 2-3mins, 5minutes there was clear visual stutter. I'm guessing either particles weren't clearing or else they weren't being offloaded when well off the screen. Similar to the second bullet: I fully appreciate that optimization isn't the top priority in gamejams but figured I'd note it just incase. I think better optimization would allow the heat to get turned up a lot higher which would add more of those cool "how did i manage to escape that" moments.