He's a 50-50 actor. When he's good, like in Kickass and Bullettrain, he's real good. But when he's bad he's absolutely horrible, like Godzilla and every superhero movie he's been in.

Edit. I want to add that I didn't even realize it was him in Bullet Train until half way through. He's pretty entertaining in it.
The movie itself suffers from a "im sooo smart and clever" syndrome that some movies have. Johnson and whoever played the girl are the good parts of that movie.