I like undertale, but I personally would want the references to be a bit more subtle, not too sure exactly how it could change, maybe limit it to one or so items. I like the idea of the spear especially.
Most of the enemies in the Jungle can be annoying if you have not prepared for it enough. Especially in hardmode, you'll need to do some decent preparation to survive. But to be more precise, those turtles are pretty awful to deal with.