The game - titled "Active Shooter" and slated for a June 6 release - is branded as a "SWAT simulator" that lets players choose between being an active shooter terrorizing a school or the SWAT team responding to the shooting.
Players playing the role of the shooter will be able to earn "game stats" such as how many police officers or civilians they kill.
In one scene shown in the game's trailer, the shooter throws a hand grenade into an auditorium, a scene reminiscent of the 1999 Columbine High School shooting, in which Eric Harris and Dylan Klebold killed 15 students.
"It turns my stomach it makes me sick to watch it", said Stephanie Robinett, a mother of three who heard about the game.More news: Man Who Saved Toddler Hanging From Balcony Awarded Citizenship
Acid added that other games that have been released "literally focuses on mass shootings/killings of people" in a way which Active Shooter does not.
"It is horrendous. Why would anybody think it's a good idea to market something violent like that, and be completely insensitive to the deaths of so many children?" the spokesperson told BBC.
When viewing other titles by Revival games, a pattern emerges of utilizing controversial and emotionally charged content to market their games.
At the time of writing, Valve doesn't seem to have clarified its position on the matter.
While the developer insists that the game (that includes realistic 3D models of children to shoot at) is not to be taken seriously, it is clear that the added caveat will not be enough to protect the developer from the torrent of criticism from both anti-gun violence groups and the community at large. This is only meant to be the simulation and nothing else.More news: Government set to eradicate mycoplasma bovis
Earlier this week, a game called Active Shooter appeared on Steam. "If you feel like hurting someone or people around you, please seek help from local psychiatrists or dial 911".
But Petty sees it differently and has already contacted the game store's parent company, Valve Corp. "After receiving such high amount of critics and hate, I will more likely remove the shooters role in this game by the release, unless if it can be kept as it is right now", the company said.
Last week 10 people were killed when a gunman opened fire at a high school in Santa Fe, Texas, and on Friday a shooter opened fire at a middle school in Indiana. The controversial game is now listed on the Steam storefront with a release date of June 6.
"Revived Games believes violence and inappropriate actions belong in video games and not (in the) real world, and insists that in no event should anyone attempt to recreate or mimic any of the actions, events or situations occurring in this game", it said.More news: PUBG sues Epic over Fortnite similarities