This cart contains the first two games I ever made for the NES called Geminim and Siamond.
Geminim is based on the logic game of Nim. The premise is simple: Several colored gems appear on the screen and you must decide who goes first or second. On your turn, you must take some number of gems from one color. After doing so, the computer will do the same. Whoever takes the last gem from the screen wins the round. After 20 rounds, the game ends and a status screen is shown saying how you did.
Siamond is based on the old Simon toys where a pattern of colors is played and you must repeat the pattern. This is done via a giant diamond broken into 4 colored diamonds. The pattern is entered by using the D-pad. The pattern will be shown faster as more steps are added to it. The game ends if you make a mistake, take too long, or succeed in a pattern of 50.
In summary, these games didn't take too long to make, but were definitely handy in learning about NES programming.