Permadeath is a good challenge, but I dont think I could do no portals. On the one hand, I dont like portals and wish I could do without them. But on the other hand, I dislike the inventory system even more. When I go explore I pick up a ton of things, when I'm full I build a portal to my base, go unload everything and teleport back to keep exploring. Without this I would go crazy not being able to collect stuff.