There have been a lot of good comments already on why one looks good and the other, well ...uh, looks like a demon hellspawn. Here's my two cents:
If I recall correctly, the people behind Detective Pikachu worked two years on the designs of the Pokémon and also studied the movements of real animals, so that they could incorporate that knowledge into the designs and animations of the Pokémon. They also consulted with people at the Pokémon Company to make sure that everything was right and that they were okay with the designs, as well as hiring RJ Palmer, who's a Pokémon fan and has been doing realistic Pokémon designs for quite a while now (he's also doing the dinosaur art for Saurian!). Also just looking at the trailer there's so many references to the games and the jokes fit perfectly to the Pokémon ... you really just get the feeling that whoever was working on this movie were fans themselves or at the very least informed themselves about the world of Pokémon enough to pull this off. Shortly put, the people behind Detective Pikachu did their homework. Oh yeah, not to mention that the movie is actually set in the Pokémon world, not in ours. (Some of the designs could have been better, but honestly, you can't tell me that the people behind this movie didn't put in any effort. They clearly put much thought and love into this project, and it really shows imo.)
Not much has been revealed about the design process for Sonic, but it at least looks like the people who did it weren't really familiar with the franchise and didn't care enough to do some research. It's not even set in Sonic's world, instead you have the same trope as many other video game movies: that somehow, this character from another world was magically transported into our world and now has to save it. Bonus points for the obligatory military incorporation.
I personally don't even mind that they changed Sonic's design a little to make it look more realistic ... but they just did some things wrong in the process ... there's plenty of fanart that "fixes" the movie design without altering too much about it, it really shouldn't have been so hard. What bothers me the most is the teeth! He has human teeth and lips, which imply a human shaped skull, but his snout is clearly elongated and animal-like. The two things just clash horribly, which just adds to the overall uncanny valley feeling.
Edit: also why is he allowed to wear shoes but not gloves. Like who made that decision
If I recall correctly, the people behind Detective Pikachu worked two years on the designs of the Pokémon and also studied the movements of real animals, so that they could incorporate that knowledge into the designs and animations of the Pokémon. They also consulted with people at the Pokémon Company to make sure that everything was right and that they were okay with the designs, as well as hiring RJ Palmer, who's a Pokémon fan and has been doing realistic Pokémon designs for quite a while now (he's also doing the dinosaur art for Saurian!). Also just looking at the trailer there's so many references to the games and the jokes fit perfectly to the Pokémon ... you really just get the feeling that whoever was working on this movie were fans themselves or at the very least informed themselves about the world of Pokémon enough to pull this off. Shortly put, the people behind Detective Pikachu did their homework. Oh yeah, not to mention that the movie is actually set in the Pokémon world, not in ours. (Some of the designs could have been better, but honestly, you can't tell me that the people behind this movie didn't put in any effort. They clearly put much thought and love into this project, and it really shows imo.)
Not much has been revealed about the design process for Sonic, but it at least looks like the people who did it weren't really familiar with the franchise and didn't care enough to do some research. It's not even set in Sonic's world, instead you have the same trope as many other video game movies: that somehow, this character from another world was magically transported into our world and now has to save it. Bonus points for the obligatory military incorporation.
I personally don't even mind that they changed Sonic's design a little to make it look more realistic ... but they just did some things wrong in the process ... there's plenty of fanart that "fixes" the movie design without altering too much about it, it really shouldn't have been so hard. What bothers me the most is the teeth! He has human teeth and lips, which imply a human shaped skull, but his snout is clearly elongated and animal-like. The two things just clash horribly, which just adds to the overall uncanny valley feeling.
Edit: also why is he allowed to wear shoes but not gloves. Like who made that decision
