Sky on Fire has just as many weaknesses as strengths and makes for an entertaining but ultimately underwhelming experience. On the positive side, you have a quite complex and intriguing story which is though at times hard to follow with its numerous characters with different interests. It basically revolves around a company that is working on stem cell research to cure cancer. The leader of the project died in a fire five years earlier and the team is now led by a greedy doctor and his humanist ex-wife. The son of the deceased leader who believes his father was assassinated in a conspiracy robs a truck with important material to put the company under pressure. A headstrong brother and his sick sister get coincidentally caught up in this conflict and while the sister grows fond of the thief, her brother rather tries to find her a cure by any means necessary. The security guard of the company who lost his wife to cancer five years earlier must decide whether he follows the greedy doctor's orders or whether he supports the group of robbers. However, another more ruthless security guard known as Wolf watches every move he makes and will go as far as he possibly can to protect the greedy doctor and his entourage. This intriguing story leads to quite a few spectacular action scenes. One can observe wild car chases, a dramatic duel on a rooftop and a dramatic showdown in the company's modern headquarters. Sky on Fire is entertaining from start to finish and avoids developing any significant ups or downs.

However, Sky on Fire also has several issues. First of all, the acting performances are truly terrible. The often cringe-worthy dialogues are offered without any emotions as the actors and actresses look as wooden as if they were robots. Since none of the actors incarnates his role convincingly, it's difficult to empathize with any of the characters. The story-telling also has issues and is often switching from one perspective to another which is quite confusing with the elevated number of characters. The fact that the villain behind the conspiracy is revealed halfway through the movie makes the film lose momentum. The special effects look obviously fake and overuse CGI techniques. The company's headquarters look as if they were copied from an old science-fiction movie which doesn't go along with the rest of the story which seems to take place in present-day Hong Kong.

In the end, Sky on Fire is a quite difficult film. It has a solid core with an interesting story, several great action scenes and solid pace that keeps the movie entertaining from start to finish. However, it seriously suffers from terrible acting, weak script writing and cheap special effects. This movie had the potential to be much better than what it ultimately turned out to be. If someone ever decided to produce a remake of this film, I would give it a chance because I appreciate the film's main ideas. However, as it is now, I can't recommend Sky on Fire which is an average action-thriller at best.