I have found two game breaking glitches:
1) Placing objects inside each other
I have achieved this through two different methods, one for objects that can be placed anywhere (chests, cropplets, tables) and one for objects that snap to a certain point (walls, foundations, floors):
Method #1 - Having your items of choice in your hotbar, placing the first object down, moving the second object inside the first in your desired position, and switching between the spot in your hotbar where your first item was and your second object, spamming left click as you do so.
Method #2 - It's kind of hard to explain, so I'll do my best. What you do is take your object (like floor, wall, pillar, etc), and you can either do the same as the other method, or you can switch between a vacant spot and the spot where you want to put your item. The second one works wonders for floors and foundations.
http://tinypic.com/r/nod6z7/9 (Method #1's outcome)
http://tinypic.com/r/1z50q9z/9 (Method #2's outcome)
2) Character hand model glitch
For some reason, this occurs after you do the previously mentioned glitch. What happens is your hand goes into the position like it's holding a mackeral, and it does not switch to the correct model when you switch to something like the spear, fishing rod, or other types of handheld objects. As far as I have tested, it does not effect anything other than the spear, and for some reason, you can't attack the shark with it, resulting in you having to reload your save unless you want your base to be slowly eaten away at.
Hope this can get fixed soon. I really do like the game, and it has a lot of potential. ^.^