Hello, and thanks so much for the feedback!
A lot of what you've said has been addressed in the new version that'll be in SAGE 2021, if you wanna check it out when it's on. :P
But yeah, difficulty balancing is the big thing I've learnt from this game and a lot of changes have been done, especially to Aracnoid, to make the game way more fun and balanced. Including adding things like a small amount of invulnerability frames so being hit doesn't feel like a one hit kill in specific places and changing parts of fights to make it easier to understand, less tedious or just removing parts (like that green spike) to make it way more fun! I do hope you'll try the game again when it's new and improved!
Lastly, with the controls; yes it is 100% true that they need improvement. With the deadline I had to cut my losses with them but I will be ensure to improve them until they are as good as they can possibly be!