It was planned in development but focus has moved on to the launcher itself. 2011M will have a functional backpack but no menu in solo. The backpack doesn't work for multiplayer currently. If anyone could help fix it after 1.3 releases I'll add it in as a patch. There is currently no plans to add in the menu as it's harder to implement than the backpack, but if someone could add that in too then I'll also add it in