Hi! I'm terribly sorry you're having a hard time trying to beat the final boss.
Some tips:
- Use the "brake" key (F) anytime you can to position yourself better.
- Move away from the corners, spikes hit you harder than Hekatok's magical bullets.
- Staying on the ground (whenever you can) tends to help some people. Like, the spiky spinning bullets just crash into the ground and disappear. The only bullets that don't collide with the ground are the green arrows. You should dodge these with dashes.
- Keep shooting! A lot of people tend to neglect shooting during the last bit, focusing on dodging all of Hekatok's attacks. Her attacks don't deal that much damage, so if you reach the end with a couple of lives, keep on shooting!
I hope that helps. I can make a small walkthrough video if you'd like, but you'll have to wait til after I finish my shift.
Thank you very much for playing!