An eagle-eyed Halo player has noticed a subtle animation on the Assault Rifle in Halo: Combat Evolved that didn't carry over to the game's remaster, Halo: Combat Evolved Anniversary. While Halo: CE released in 2001 on the original Xbox, Halo: CE Anniversary released on the Xbox 360 in 2011 and is a ten-year celebration of the first Halo entry, featuring updated graphics.
Halo's original developer, Bungie, parted ways with the IP after the release of Halo: Reach in 2010, leaving Microsoft's 343 Industries as the primary developer working on the franchise and striving to satisfy Halo fans through armor changes and other works. 343's first release after Bungie's departure was a remaster of the first Halo game, titled Halo: CE Anniversary, which was meant to celebrate the tenth anniversary of the series. The game features remastered textures and audio, including reused assets from subsequent Halo titles, but players also have the option to switch to the original graphics at any time. Though some fans prefer 343's modernized take on the first Halo entry, others regard the updated graphics as unrefined and not in line with the original game's art style.
One small but notable difference between Bungie's Halo: Combat Evolved and 343's Anniversary edition was spotted by CrassusMaximus and posted in a video on the Halo subreddit. As it turns out, the ejection port on the Assault Rifle in the original graphics opens and closes upon firing to release each spent shell casing. In the Anniversary graphics, however, the ejection port remains static when a shell casing is released. This small animation is easily missed because the right side of the Assault Rifle, where the ejection port is located, can't be seen by the player who's using the weapon in either graphics mode. To view the discrepancy, a second player must stand to the right of the first player and switch between graphics settings while the first player fires the Assault Rifle.
The absent animation on the Assault Rifle is a small omission on the scale of everything that goes into Halo: CE. Indeed, the animation can't even be seen by a solo player. But it's the many small details of a game that add up to create truly immersive, atmospheric conditions or take away from the overall experience. For instance, S-192 in the comments notes that the shell casings in the Anniversary graphics also appear too bright, as well as too large relative to the size of the ejection port. The revelations are not just a knock against the Anniversary graphics; they illustrate the care that went into the small details.
To its credit, 343 Industries is actively working to improve its port of Halo: Combat Evolved as part of Halo: The Master Chief Collection. The corrections made so far include proper fog, bump mapping, shield lighting, and graphics issues from the original Xbox build of Halo: CE. Given these recent fixes, it's not impossible that 343 will go back and add the Assault Rifle ejection port animation to the Anniversary graphics before the next mainline Halo game, Halo Infinite, launches later this year.
Source: CrassusMaximus/Reddit