Thank you for playing! I think I see what happened with the rolling for you.
Basically, the roll makes you move faster, so you can get around faster by spamming it, and gives you i-frames but only during the roll. You can roll immediately after rolling with no cooldown to zip around.
But there are the slug ghosts that have dark trails, and when you touch their trail, blorb gets covered in slime and can't roll for a few seconds. That probably was why it felt like rolling had a cooldown during the fight.