The online game unfolds from the point of view of an attacker, aiming a weapon down a school corridor or throwing a grenade into an auditorium. The character creeps around corners and up staircases. Bullets spray, blood spatters. SWAT team members are shot dead. Civilians are splayed out on the floor.

The game, Active Shooter, was scheduled to be released on June 6. But it ran into controversy after several recent school shootings, including massacres at high schools in Santa Fe, Tex., and Parkland, Fla.

Parents of victims of the Parkland shooting amplified the opposition to the game, calling for boycotts and seeking to block its release.

“Nothing will bring my daughter back, but there is a role for adults to have in terms of being responsible, and this is not responsible,” said Fred Guttenberg, whose daughter, Jaime, was one of the 17 victims of the Feb. 14 shooting in Parkland. “This is gross, this is profiteering, this is unacceptable.”