The Mega Shark movies are the kind that aren't to be expected much from, but even with that in mind I personally didn't consider either of them particularly good, some fun moments, mostly for the so-bad-it's-good value there was, but mostly they were too cheap and silly to take it even for what they were. Mega Shark vs Kolossus is one of the better movies in the series along with Mecha Shark, but for me it was only passable at best.
While the special effects are usually terrible in the Mega Shark movies, and Asylum/SyFy movies in general, they don't look too bad here. The two title monsters are not as cheap as feared and succeed in giving their scenes personality. The shark could have looked far worse as far as low-budget sharks go, a good amount of detail went into it actually, and is actually pretty fiercely menacing, rather than being goofy or bringing unintentional humour like most low-budget sharks. The kolossus character is imposingly designed and a cool, heroic character, the two's chemistry is great and help make their scenes (of which there's generally not enough, and they're a little too short) watchable. The last act especially is a lot of fun, and makes one wish that it came earlier and that the rest of the movie was to its level. The scenery is very nice and the underwater scenes are shot well. Didn't think much of the acting on the most part, but Amy Rider did a nice job.
However, the rest of the acting is pretty dire, especially from the captain whose actor seems to be channelling Samuel L. Jackson and doing so while overacting embarrassingly poorly. Illeana Douglas is also somewhat bland. The script is a mess, with the human drama scenes with its messy mix of scientific gobbledygook and military jargon struggling to make sense and they doesn't ring true at any time (actually sounding made up on the spot), and the humour parts are cheesy and contrived, the dialogue being so awkwardly awful it's cringe-worthy. It also does nothing to develop the characters or make them engaging or identifiable, they're little more than walking clichés written in the most cardboard way.
Despite coming to life in the last act, most of the movie's story is tiresomely ridiculous and dull, trying so and too hard to over-the-top and fun (even in the serious scenes, that as a result became overheated and ham-fisted) that it's tiring, especially when all the Mega Shark movies take that approach (concept-wise there's not much new either) and when you see it so many times with The Asylum/SyFy. The editing tends to be haphazard and the movie is lit in a drab way, while the direction only shows some personality in the last act but is flat everywhere else and the music is at best generic.
Overall, while one of the better movies in the Mega Shark series it is only reasonably passable. 4/10 Bethany Cox