As Hollywood races to find new intellectual property to adapt, video games with a built-in audience of millions could be the next frontier for blockbusters—but only if studios get them right by appealing to core fans.

The Pokémon flick is the first of two live-action video game adaptations slated for release in 2019. The other, Paramount’s Sonic the Hedgehog, debuted its first trailer last week—and it didn’t go over well. Fans mocked the dated humor and the quasi-realistic design of the title character. The vitriol was so bad that Sonic’s director said the character would be redesigned before the film’s November release.

Analysts now expect Detective Pikachu to be a hit for the very reason they say Sonic could be a flop: because it embraces the source material while using a fresh approach, unlike many previous video game adaptations.

Audiences have reacted almost completely differently to each trailer. On YouTube, the Sonic trailer has 625,000 dislikes and 351,000 likes—a far cry from the 1.4 million likes versus 68,000 dislikes for Pikachu’s first trailer.

“The message is loud and clear… you aren’t happy with the design & you want changes,” Sonic director Jeff Fowler tweeted on Thursday. “It’s going to happen. Everyone at Paramount & Sega are fully committed to making this character the BEST he can be.”

But analysts aren’t convinced.’

“Sonic reminds you of all the bad video game adaptations that have been put out,” says Jeff Bock, senior box office analyst at exhibitor relations. “The fact that they got it all wrong here on their first swing is a bad sign.”

Bock calls video game adaptations a “dark mark” in Hollywood’s history. He’s not wrong: with a few exceptions (like Angelina Jolie’s Lara Croft: Tomb Raider in 2001), video games bomb at the box office. One of the biggest disappointments was 1993’s Super Mario Bros., which generated just a $20.9 million gross on a $48 million budget—and scared Nintendo away from making more movies for decades.

The 1993 Mario had little in common with the video games, with few of the fanciful character designs or settings beloved by fans. Bock says he gets a similar feeling from Sonic’s trailer.

“To be successful, you need to take a page from Marvel and really appease the hardcore fan,” he said. “It doesn’t seem like the people that made this really understand or love the property.”

Detective Pikachu, on the other hand, “completely nails the world of Pokémon,” according to IGN Editor-in Chief Terri Schwartz after an early screening. The character designs seem ripped straight from the Pokémon games and cartoons, according to the trailer and reviews. The first trailer even used music from the original game’s soundtrack.

“The amount of detail specific to the property that’s packed into every corner of the frame, it really feels like it’s made by people who love Pokémon…which hardcore fans will appreciate,” says Patrick H. Willems, a filmmaker and video essayist who says he’s spent a lot of time pondering just how Hollywood studios can get video games right.

Meanwhile, Sonic’s trailer features Coolio’s “Gangsta’s Paradise”—which only seems connected to the video game by virtue of also being released in the 1990s.

Willems described Sonic’s big-screen design as a “bizarre hybrid” and says the film looked like a formulaic kids’ movie where a human teams up with a CGI animal (James Marsden, who plays a human police officer in Sonic teamed up with a CGI rabbit in the 2011 film Hop).

Then there’s the question of star power. Gitesh Pandya, editor at BoxOfficeGuru.com, says that Ryan Reynolds should bring in audiences as the voice of Pikachu. He’s a more relevant star than Jim Carrey, who plays the villainous Doctor Robotnik in Sonic.

“Jim Carrey is not the box office powerhouse he used to be,” Pandya says.

Of course, celebrities can only draw so many viewers to an adaptation, as such projects need to appeal to fans of the original work. But video game movies can’t just coast on nostalgia and recognition, especially since films don’t have the interactive element of the source material, Willems says. Detective Pikachu isn’t just putting a video game on the big screen, and that could be a strength.

“It seems like they have the world of Pokémon and are telling a story within that world, rather than trying to take the structure of a video game and applying it to a two hour film,” he says.

Pokémon has seen some success with animated films, including a $163 million worldwide gross for 1999’s Pokémon: The First Movie, but a major live-action hit could kickstart a wave of movies in the universe. Box Office Pro predicted a breakout weekend for the film, expecting it to make at least $75 million in North America over its opening weekend. Legendary Entertainment is so confident in the movie that it’s already working on a sequel, according to the Hollywood Reporter.

As movie franchises like Marvel continue to break box office records, smaller movies have to make the bulk of their profits in their opening weekends before the next big event movie comes along. While Pikachu doesn’t have much competition opening alongside it when it’s released on May 10, Disney’s Aladdin remake comes out just two weeks later.

Sonic is in an even worse position: it faces stiff competition opening weekend, including an adaptation of Stephen King’s The Shining sequel Doctor Sleep. And just two weeks later, Disney’s expected box office behemoth Frozen 2 hits theaters.

“This has to open huge,” Bock says. “But it doesn’t seem like this is going to catch on with anybody but young kids or maybe families.”

Both Bock and Pandya say that Sega and Paramount have time to course correct—and that a new trailer with a redesigned Sonic could generate the hype the studio was hoping for with their first go-around. That said, Bock is skeptical.

“Everything they could have done wrong, they did do wrong with that trailer,” Bock says.