Alien Vs Predator: Requiem didn’t wow fans of either popular sci-fi creature but the movie’s original, brutally dark ending would have been the worst in either series. When Alien Vs Predator arrived in cinemas in 2004, audiences were excited to see two titans of sci-fi horror go head to head in a battle for the ages. Unfortunately, despite the underrated Alien Vs Predator securing the directorial services of Event Horizon helmer Paul W.S. Anderson, the end result was dismissed by critics as a sanitized PG-13 effort that lacked gore and scares alike.
Directing duo The Brothers Strause brought far more gore to their 2007 sequel, the hard-R rated Alien Vs Predator: Requiem. Despite a marked increase in bloodshed, the movie's critical reception was even harsher, with everything from its flimsy storyline to its terrible lighting being lambasted. Even for a film that was combining two franchises filled with shocking deaths, Alien Vs Predator: Requiem had an issue with taking too much gleeful delight in killing off countless characters.
One major issue viewers had with Alien Vs Predator: Requiem was its nihilistic tone. What makes it all the more shocking is that it almost ended with a blackly comic Night of The Living Dead-style finale, which would have really nailed home how little it cared for its human characters. According to the sequel's audio commentary with the directors and producer John Davis (via AVP Galaxy), an alternative ending showed the special forces team that greets the survivors at the end would have killed them all after nominal hero Dallas hands over the Predator's Plasma Pistol.
For reference, even in the existing “hopeful” cut of the movie, the ending sees Dallas’ brother Ricky badly wounded from an earlier attack, Ricky's love interest having abeen callously killed off during the finale's carnage while most of the town was nuked by the goverment to contain the spreading Xenomorph threat. The proposed Alien Vs Predator: Requiem alternate ending was felt to be too depressing, so the special forces massacre was dropped.
Alien Vs Predator: Requiem was rightly criticized for taking uncomfortable delight in killing off innocent characters including vagrants, numerous children, and heavily pregnant women in the infamous maternity ward sequence, so ending with “the government killed everyone regardless” twist would have been literal overkill. That said, the revision of Alien Vs Predator: Requiem's ending wasn’t enough to stop original Alien director Ridley Scott from (essentially) killing the entire cast of Alien: Covenant’s in its brutal twist ending a decade later.