As a general rule, for works created after January 1, 1978, copyright protection lasts for the life of the author plus an additional 70 years. For an anonymous work, a pseudonymous work, or a work made for hire, the copyright endures for a term of 95 years from the year of its first publication or a term of 120 years from the year of its creation, whichever expires first. For works first published prior to 1978, the term will vary depending on several factors.
And assuming we're talking about a videogame made before 1978 (such as pong, in 1972)...
http://www.copyright.gov/title17/92chap3.html
QUOTE said:
the term of copyright shall not expire before December 31, 2047
QUOTE
Any copyright, in the first term of which is subsisting on January 1, 1978, shall endure for 28 years from the date it was originally secured.
[...]
At the expiration of the original term of copyright in a work specified in paragraph (1)(B) of this subsection, the copyright shall endure for a renewed and extended further term of 67 years