Sometimes you come across a movie that takes no risks. It's light on story, avoids character development, and focuses on getting to the next scene as easily as possible. Mario Bros. Doesn't have any inherent plot holes or issues, but it tends to leave you in a state of just being a viewer rather than participating in the movie. In the end, it's not bad per se, but comes off as flat and lifeless.
The positives are all agreed upon by anyone who likes it, because the positives stand out by not being able to be compared against anything else. People have fun with the action. They love the Easter eggs. And the composed music is good. The action is done well, but without much dramatic weight, only carry the movie so far. Easter eggs don't nor should have any bearing on how good the ovoid is. The music was well incorporated, minus the pop songs that truly don't work.
It's not good enough to play things easy, and rely on fans to spot visual Easter eggs, to call the movie good. It's average at best mostly because it was watchable and didn't have any outright flaws. It just didn't take chances that could've ended up becoming flaws. Even if you had a good time watching it, there's not enough value to see it again. If you're a fan, check it out. If not, you won't miss a thing by skipping it.