Start-Up is an inspiring story that's a realistic, fun story that is very enjoyable to watch with a few shortcomings.

Story:
The storyline about Sandbox and the main casts' journey of starting a business and expanding is very inspiring and enjoyable to watch. Everything was done so well, but one thing I wish could've been done better was the romance. By the time Nam Do San's charm was revealed, Han Ji Pyeong had managed to take over until he sometimes seemed more like the main lead, but otherwise, Start-Up's story was uplifting and enjoyable to watch.

Acting/Cast:
The acting was great. At times, Nam Joo Hyuk's acting wasn't as up to par compared to Kim Seon Ho's, all the actors did really well. Nam Joo Huk and Suzy had amazing chemistry and so did all of Samsan Tech. Suzy and Kang Han Na also had really great chemistry as sisters. Seo Dal Mi's family also had such great chemistry.
Overall, the chemistry of this cast was out of the roof with superb acting.

Music:
The OST for Start-Up was one of the best OSTs I've ever heard. "Future" by Red Velvet is definitely one of my favorite songs ever and while there are too many to list, the rest of the OST's songs are amazing as well.

All in all, Start-Up had some shortcomings, mainly how the romance was written out, but the cast's superb chemistry and acting and the rest of the well-written story outweighed it. Start-Up shows the story of three friends running a start-up. They realize they need help as they try to make the most of the scarce opportunities in front of them. This story shows them finally succeeding, through many hardships. I recommend you watch this very uplifting and inspiring story. You won't regret it :)