It would be nice if you could destroy your water purifier/crop box/grill without destroying the foundation beneath. Maybe have a feature on the hammer to destroy structures and get some material back. Also I broke a foundation in the middle of my raft (in order to get rid of my starter structures) and I cannot add a foundation there. It looks like the foundations can not be placed without an empty space on one side.
Great game! I look forward to future developments!