This game absolutely nails the presentation, the visuals are fantastic and the music sets the atmosphere incredibly well, but it has some issues when it comes to the actual gameplay itself.
What I feel are the issues -
1. The bullet patterns which don't include randomized bullets come out a bit too quickly and you have to rely on memorization to be able to dodge them consistently (Or at least I did, but my reaction time is pretty bad, so maybe others have no issue with this). I feel like the dash was made with reacting to these in mind, but I had no luck using it to dodge in these situations.
2. Many bullet patterns feel very similar, they're either aimed at a certain spot or fairly random, neither of these are bad bullet patterns, but if the game had a little more variety in terms of the things it throws at you this would be solved without having to change the existing ones (Although, understandably maybe it wasn't possible within the time constraints).
Either way, I think this is an interesting and sort-of poetic take on the theme and I am a big fan of how the spider uses it's several eyes as bullet emitters, I think that has a lot of potential for interesting bullet patterns (If I remember correctly, it was the second-to-last pattern in phase 2 which made me notice this, that one was pretty cool in particular, just a little too fast for me).
This may seem a little harsh compared to the other comments, but I only commented because I feel like this has a lot going of good going for it and a little extra push could make this absolutely fantastic.