I found the prayers and found them useful. But I deal zero damage to Tewi after spending what I'd consider to be a decent amount of time for a jam game and most of it spent on grinding combat. I never played Runescape, but I managed to mostly figure things out. I don't think you need a tutorial, but a more complete game page on itch.io *might* help.
One thing I never figured out how to do is to get rid of non-consumable items from my inventory. I really wish I could eat those books...