I've seen Detective Pikachu and I have my 2 cents on video game movies, they're a mixed bag and incredibly difficult to do. First, the elephant in the room with the yellow rat ears.... Or pikachu ears.
The Detective Pikachu movie was disappointing in terms of the story, they could not write or tell a good mystery; in-fact I was able to figure out the mystery and piece together everything about the first leg in and the detective isn't really a good detective, it or he can make a lot of good guesses but the answers are delivered to them on a silver platter and this misdirection is too easy to figure out. The video game based on this makes better mysteries than this! The mystery flopped hard; if you want to write a better mystery, look to Scooby-Doo from the 80's or the Batman movie The Mask of the Phantasm for inspiration or how to.
THE FLIP-SIDE, How the world is in the movie? It is gorgeous and makes me, literally, believe that they CAN make a live-action pokemon movie. Granted when I saw the Pikachu artwork for the first time, I said no way, but seeing how the character moves, how all of the pokemon move and operate and the level of detail, balancing between realism and fantasy they did with the art direction; if they did it again with a different movie premise, then I believe they can do it and I mean really do it. Even pokemon battles performed in the middle of the3 movie are pretty well done and not dis-jarred by a trainer calling out a move in that side panel in the anime... I guess to put bluntly, if they wanted to do a live-action Pokemon movie, they can do it and this movie proves they can pull it off.
Video game movies are just as hard to grasp as video games based on movies, but in reverse order. Where game designers have to expand the content of a movie to fill their video game, such as more missions, stories or mini-games that make it feel pointless and less like a game; Movie developers have to explore and condense on the world building and expanding on characters....
I guess, a prime example is Super Mario and the Super Mario movie that came out a ways back. Eliminating what you do in the game, what is the basic story of Super Mario? Save the Princess Toadstool/Peach from Bowser using jumping and hammers. Mostly the first. Ok, how can you write that to a live action script to start? Do you pull off what they did with Page Master or leave it as full live action? If the former, how do they cross from the live action world to a video game world with already designated characters? Are there any weaknesses and fears you can exploit or changes the characters can explore to become stronger from or wiser? If the latter, how do you add Blocks, Super Shrooms, Bomb-Bomb's and Goomba's? How can you keep a surreal story straight to understand instead of being all over the place? This is the difficult challenge that's harder and harder to tackle the more you ask questions like this. Some questions are easier to answer.
Others? Not really. Mario is already seen as a hero to more children jumping into this world of polygon and pixels that he's already confident, he has no weaknesses and not really more character to develop, throwing out the 'GAME THEORIES' and everyone's hardcore speculation and leaving this as an Ockham's Razor, the simplest answer being the best for the time being... If I had to place it, you can think of Mario as the Boy's version of a Disney Princess, a flawless hero who doesn't give up... Which is fine, that's how he's created and his attempts to save the woman or princess he loves. The guy getting the girl, happily ever after until a new Mario comes out.
Does this mean I think video game movies are impossible? No, I believe they can be done well, TV Series even.
The first Tomb Raider movie did this and they did it about perfectly. Lara Croft being a Billionaire, Raiding Tombs, constant and daily training on her estate. They however evolved her as a character in interesting ways. Such as she and the antagonist sharing their same interests to a point where they could be lovers at one point, but still remain indifferent on their goals for a treasure they are seeking, trying to beat each other to a certain treasure but needing each other's help to attain it.
Then the Mario anime or OVA and even the Mario comics Nintendo published do a far better job at describing the characters, filling in blanks a film maker can even use to create a Super Mario movie. The OVA being surreal enough that it deserves a western release. The Mario Comics? Published by Nintendo Power and re-released again that you can probably them on a digital comic retailer today, they give more life and ideas where you can take Mario despite what he is or does.
A movie based on a video-game, I believe, can be done and it can be done well. We just need the right people with the right passion and the right writers along with the proper actors and mediums to make it work.