Duke Nukem: Critical Mass

After Time To Kill and Zero Hour, Critical Mass is another Duke Nukem game involving time travelling in its scenario: the Earth Defense Forces are monitoring the future, using a time machine, but all people they send there did not come back and lost contact. Thus, they send in Duke Nukem to save the day. As he gets there, Duke finds out that aliens have invaded Earth (*again*) and do experiments on Earth's women. This, of course, calls for another round of alien-ass-kicking. Similar to Manhattan...