I have a few ideas what you can bring in the patch
1.water station ... it would be like .. collecting berries ... just you get no item and fill up your thirst a little bit ... so you need to drink more times.
2.collecting wood by cutting down trees with axe ... the outstanding trees must be dynamic
3.making it a multiplayer game and present it on steam ... it will boom like hell! $$$
4.bringing in cantines and bottles to collecting water ..
5.running faster ...
6. animals ... so they would be like npcs just walking and stand for a while ... and if you kill them they drop meat and pelt
or... you need to cut them off with a knife.
7. cars .. hmm.. i dont know .. how this will be realized ...but it would be great .. but just go the classic way with the v2s pickup
have a great day and i love your game!