The Game Boy (ゲームボーイ) was an 8-bit handheld video game device developed by Nintendo. It is the first handheld console in the Game Boy line, and was created by the inventor of the D-Pad Gunpei Yokoi. It was released on July 31st 1989 for $89.99, which would equate to $181.24 today.
July 31st, 1989 Source: vintagecomputing.com
Included Tetris game pack.