This movie technically came out before the series, please watch this first if you can.

The game designs, characters, costumes and hair are all impressively beautiful.
The main couple are warm and natural, Cao Guang/Zhen Shui did a good job at being the "villain". As much as I like Li Xian, his character is too small to stand out, even though he's the hot headed friend of Xiao Nai.
The love story was very rushed. In-game they barely interacted, unless it is all off screen. They met twice and he embraces her and tells her about everything he's working on. Yet again, if there were more time they spent together the audience doesn't really know... and 3rd time they kiss. WHOA! Down boy! Calm down! Even if it's hot and dreamy.

COMPARING the movie to the series.
Glad they got Ryan Zheng to be Zhen Shui, who was great at being the villain. Zhen Shao Xiang's over all story was really good.
Cao Guang becoming his own character was also amazing, "evil" in his own way. His story is also cute.
KO in both movie and story are too different and both are good. Series version of KO does feel like he's more cool, but so awkward.
Weiwei and Xiao Nai movie version takes the cake. If these actor and actress were the series, it would have been perfect. I remember watching the series and thinking, story's good but the actress looks too angular. The couple is cold and distant. Although the series gave more background story and build their relationship. Most people like Yang Yang, but maybe he didn't really click Zheng Shuang and vice versa.
Obviously, the series had more time to develop the characters, story and bonding. Watching the movie after the series might be more satisfying and might not feel like Xiao Nai is going too fast with Wei wei.