Zombie Tidal Wave

This is a bad movie, no doubt about it. With horrible CGI, bad dialogue, acting and characters, this would be considered a disaster if it was made and taken seriously. It wasn't, and what we have left is this film from the producers of Sharknado that looks like a Playstation 1 game, make that what you will. The film also tries to have some emotional scenes of people dying, but when that's in the same movie as blue zombies from the deep blue sea causing huge tidal waves containing them, it's not a good tone.The zombies are also curious. There could be many surrounding an area, and by the next time we see them, there is only like 4 or 5. Also, at the end there is a zombie that can actually hold and fight the character Hunter, even though every single other zombie couldn't. What is this movie, and why is it so bad, yet sometimes charming and entertaining?