Future Wars (1989)

In the year 1989, a simple window cleaner is working outside of a skyscraper. Intending to play a prank on his angry boss, the unlikely hero discovers a secret passage leading to a time machine along with mysterious alien documents. Operating the device transports the protagonist to the year 1304, where he is given a seemingly ordinary task of rescuing a lady in danger. However, he soon finds out about a much more. The first in what was supposed to be a series of games about time travel but no other games were made.