Animal Contest is likely the result of taking a recreation of the card game War, and attempting to reskin it into something else in a way which makes it downright nonsensical.
Credits Screen#
Pressing Up, Down, Up, Left, Right, Left, B on the title screen will briefly display a credits screen. Nature Color Game is one of several aliases used by Nice Code, and "PJ" most likely refers to the Power Joy series of Famiclones which many Nice Code games have been released on.
Revisional Differences#
An alternate version of this game exists which alters the credits screen. Entering the code on the title screen will briefly display a black screen without the credits. The text still exists in the ROM, and editing the color palette for this screen will cause it to display correctly.
(Source: Original TCRF research)