This is just a rotten cartoon. I honestly don't think it would entertain anyone over the age of six.
If you don't know what Batman Unlimited is, it's essentially a line Batman universe toys which, until now, didn't have any cartoon or comicbook to back them up. This movie attempts to do that for kids... but yeah, it's not even worth the $3.99 digital view price.
The first thing you'll notice on viewing it is that, unlike previous Direct-to-DVD DC Comics cartoons, this one doesn't fly under the "Warner Premier" banner. Meaning it has none the writing pedigree or production values of movies like "Under the Red Hood" or "Batman: Gotham Knight." And that shows in how full of plot holes and contrivances this toon is; such as the bat-dog-robot-motorcycle and the clumsy attempt to tie in the Batman Beyond suit, which is instantly forgotten to move on to the next in a line of "neon street luge batman" bat costumes you get throughout the viewing. Villains are given no more reason to work together and no more plot than the fact that they share an animal theme, and one of the heroes just happens to be hanging around Gotham City despite not even having a connection to Batman ever mentioned.
In other words, the movie is a 90 minute toy commercial, and it makes the original Thundercats and Silverhawks seem like Shakespeare by comparison.