I believe you need to use a voltage divider for the LDR to give an analogue input. The following link gives more details.
http://www.doctronics.co.uk/voltage.htm
As the Raspberry Pi doesn’t have analogue inputs the CamJam kit uses time to charge as the measure of light.
An LDR is just a resistor that changes it’s resistance depending on the amount of light that hits it. You cannot get a value from it by just connecting it to 5V.
I’d suspect your analogue pin is floating or the value is dependant on the internal resistance of the Crumble.
