The so called 'silver' games was released in 1980 and was the first in the game & watch series. The first game released was 'Ball' and was followed by 4 more games before Nintendo delivered the gold edition (Manhole 81-01-29), with only minor changes in colour. Very hard to find this days.
 

AC-01 1981 BALL
RC-04 1980 FIRE

CN-07 1981 HELMET
FL-02 1980 FLAGMAN

IP-05 1980 JUDGE


LN-08 1981 LION
MT-03 1980 VERMIN
MH-06 1981 MANHOLE