Thank you and I'm glad you liked it!
Yea, the difficulty can be a bit variable due to the break mechanic (~1% per use on most items), but some items do more or less against certain enemies (all the magic rods instakill slimes but they resist a lot of swung weapons, for instance).
I'm so curious where these crashes are coming from because I didn't run into them at all in testing but multiple people have reported it. I'm pretty sure it's a web only issue, but do you remember what the error was that was in the console?
If you do want to give it another go, you can rush the end in the castle with 60 kills/souls by going up the big stairs, most of the castle is optional for extra items. There is also a chest dupe you can exploit that I left in on purpose - open the chest slightly from the side to only open half the chest.