Like in this circuit you need to tilt the Box in particular sequence to open the box. This idea is very creative and simple. You just need to have an Arduino Uno, Accelerometer (MMA7361 Three Axis ...

Arduino Uno board (or clone) plastic project box (search for "ABS Plastic Electronic Enclosure Project Box Black 103x64x40mm" on Banggood, it's about $3.5) 3.5mm panel mounted stereo jack socket (eBay ...