Refrigerator Puzzle Box

You're hungry. It's time to eat. You want a pizza, but it's locked in the freezer. You have to figure out how to open the freezer and get it! Otherwise you will starve, and it will be sad.

The box has various mechanisms to unlock it completely that give it 7 steps to unlock when constructed. It has 20 pieces to individually print. I uploaded a zip file of them all together if that is easier. It's not print in place but it will make a really neat puzzle when constructed. Note that the grate is what's used to hold the pieces in the lower door together and might take some care to install. 

If you have any questions or are into puzzle boxes let me know! This is my first one but I really enjoyed designing it and want to do more. Designed with Tinkercad.com, printed with the Bambulab X1C.