Keycode Conundrum [ended]

A train pulls up to the station, but the door is locked! It needs a keycode. Can you work out what the code is? Looking through the windows, you can see the games inside are:

Domina, Flat Kingdom Paper's Cut Edition, Kathy Rain, N++ (NPLUSPLUS), Kingdom: New Lands, Obduction, Orwell: Keeping an Eye On You, Rusty Lake: Roots, Tropico 5, Tropico 5 - Espionage, Tropico 5 - Waterborne.

You can try and enter the keycode here

Solution:
First, notice that pictures 3 and 4 imply that the code both starts with 1 and starts with 9. This is impossible. In fact, it must be that the fourth image is upside down, and actually the code ends with 6. So we have 1677, 7706 and 747 and the code starts with 1 and ends with 6. It's tempting to begin by doubling up the two 77s to get 167706, but then we don't have space to fit in the 747, so actually the answer is... 167747706