Electronic Arts is facing strong criticism over the in-app payment system in its Dungeon Keeper game.
Many said the game was "unplayable" unless they spent significant sums to speed up progress and get upgrades.
EA said it had designed the game to fit in with typical patterns of mobile play and people did not have to spend money if they did not want to.
Peter Molyneux, maker of the original Dungeon Keeper, said EA had not got the game's balance right.
EA released the mobile version of Dungeon Keeper early in February and soon afterwards it started to get negative reviews on many tech news sites.
Reviewers criticised the game's aggressive use of in-app purchases which involve paying real money for an in-game resource called gems.
Reviewer Jim Sterling from The Escapist said the constant need for hundreds of gems undermined the game's claim to be "free to play".
"It's free to wait, but not to play anything," he wrote. "There's nothing to actually play."
Dungeon Keeper gives the player the job of constructing and running an underground lair to which they attract monsters that are then used to defend the place against attackers. Minions called imps dig out rooms and corridors to create the dungeon.
Many complained that the imps work much too slowly unless players buy gems. Without this resource the game makes players wait four hours to dig out some types of territory and 24 hours to dig out rockier parts.
Peter Molyneux, who designed the original 1997 Dungeon Keeper game, said he too was shocked when he saw the time it would take to dig out some sections of the map.
"I felt myself turning round saying, 'What? This is ridiculous. I just want to make a dungeon. I don't want to schedule it on my alarm clock for six days to come back for a block to be chipped,'" he told the BBC.
Mr Molyneux said some of the criticism came from fans of the original who simply wanted an updated version of the game they fondly remembered.
He added: "I don't think they got it quite right, the balance between keeping it familiar to the fans that were out there but fresh enough and understandable enough for this much bigger mobile audience."
In response to the continuing criticism, an EA spokeswoman said it thought it had got the balance right.
"We specifically built Dungeon Keeper around typical mobile play patterns - that is, checking in a few minutes here and there throughout the day," she said. "This way of playing, we've found, allows fans to naturally progress through the game as a free player."
"We believe we've designed an experience wherein players don't have to spend money if they don't want to," she added.
Internal testing had proved that it could be enjoyed as a completely free experience, she said.
In an interview on Tab Times EA said that the number of five star reviews the game had on the App Store and Google Play showed how popular it was.
However, in response, many people pointed out that Dungeon Keeper currently had a rating of 0.3 out of 10 on crowd-sourced review site Metacritic. Many of those posting reviews and comments on Metacritic decried how much it cost to get gems to complete some elements of the game quickly.
Analyst Thomas Baekdal said EA could experience a "backlash" over the game and warned that its use of in-app purchases was evidence of a dangerous trend.
"It's only a matter of time before the friction between what people want and what game studios offer reaches a point where the whole thing collapses," he said.