What If Half-Life Was Made in 1989?

Half-Life was made in 1998 and it was considered one of the best first person shooters out there. What if the game was made nine years earlier?

Changes

 * The gameplay would be changed to a Metroidvania platformer with modern day releases changing to the classic first person shooter gameplay.
 * More Half-Life games would have been released due to this.
 * The Half-Life world would be more fleshed out.
 * IDW would be publishing a comic book series set in the universe.

Games

 * 1) /Half-Life/ (1989)
 * 2) /Half-Life 2/ (1991)
 * 3) /Half-Life 3/ (1994)

Comic
See /Beware the Combine/.