First video is a test program written in BASIC language:

Second video is a brief gameplay of Zanac. Video shoot is terrible as I was playing the game with one hand and hold the camera with another (both videos were did like that)

It is possible to notice some lag from the analog stick and the ship moving in the screen.  As the controller is being sampled at 100Hz (10ms) this lag is not caused by software, it is caused by the time I spent to move the stick to the opposite position until it passes a given threshold around the center. It can be reduced either by lowering the threshold value or by deducing the movement direction by the rate of change of the analog stick.