I like how the strength balance with enemies scales quickly: the big unbeatable slimes become easy loot and I started to ignore the small ones. but the battle are maybe a little bit easy. Very quickly I didn't have to care about my HP bar because it will never go down.
I beat all the water slimes but I didn't find my way to the other species yet (I killed just a few ones, and then I was blocked everywhere, I didn't find a way to them).