Is your Nintendo Gameboy Tetris cartridge original?
Here are photos my authentic Tetris game cart.
The front of the board has the words:
It contains a blob chip, a small capacitor C1 103, and an unpopulated space for capacitor C2 100uF+
There is also VDD 1 which signifies which is pin 1 (voltage), pin 32 and GND
The back of the board has no noticeable features.
Finally the front of the cart has Nintendo GAMEBOYTM logo embolded on the plastic.
The sticker has the words DMG-TR-UKV, MADE IN JAPAN. The TETRIS logo, ORIGINAL, GAME LINK, GAME PAK logo.
Beneath these are Nintendo and an Original Nintendo Seal of Quality badge. The right side has THIS SIDE OUT.
Another feature of the sticker is the letters 22A marked just above the seal of quality logo, which is almost impossible to see on the photo.