The Windows PC version of Metal Gear Rising: Revengeance may be outfitted with always-online DRM, although the online requirement may also result from a bug in the game, according to reports on NeoGAF and in reviews on Steam.

Konami released the PC port of Revengeance today, and its Steam listing makes no mention of an online requirement. But disgruntled Steam users are giving the game negative reviews, citing the apparent presence of always-online DRM.

"This game will not run without an internet connection. And unless your internet connection is completely stable it also doesn't work. Try opening it without an internet connection and it [immediately] closes. When my internet connection drops out while playing, the game instantly bombs out," said Steam user TescoValueName.

"Looks like Rising doesn't work at all if your internet goes out or if you put Steam in offline mode," said Parsnip on NeoGAF.

However, a problem with Revengeance's use of the Steam API may be at issue, rather than DRM instituted by Konami. According to NeoGAF user Guess Who, the game will work in Steam's offline mode if the user has installed a modified version of the steam_api.dll file — which could result in their Steam account being banned. J.P. Kellams, creative producer at developer Platinum Games, said on Twitter that he's unsure of the root cause of the problem, and is looking into it.

We've reached out to Konami for more details, and will update this article with any information we receive.

Update: Konami addressed the situation on its Twitter account this evening, saying it's working to fix the issue.

We are aware of the offline play issue for Metal Gear Rising for Steam and are working on a fix. Please stay tuned for more updates! — Konami (@Konami) January 10, 2014

On Twitter, Platinum Games' Kellams confirmed that the issue is related to a bug, and not intentional.