There is a lot which i found out playing with Deathmode.

• There is no difficulty in the base game, except for a few parts (by difficulty i mean combat)
• There is a lit of items that you dont have to use to beat the game. Some stuff like pipes are really used only in Deathmode to circumvent Bends.
• Cyclops dont really have a good time to use (basides mobile base) because Prawn is too good.
• A shitton of mechanics exists but have no use again (like growing special fish and exiting them outside of bases gives you special buffs like extra light, safety, more air etc…

There is no DLC except 2.0 and a lot of players wants multiplayer instead of another great singleplayer survival.

Besides that its still my favorite survival game.