So, as a disclaimer, I am a massive fan of Park Seo Joon, so I'm gonna be biased in this. (very very biased in this.)
The acting in my opinion is brilliant, they don't have plot armour, they act as what would be expected from any police student in that situation. And, oh me oh my, I haven't laughed so well since yesterday. The humour is fantastic and what little school scenes there are, they're highly relatable.

Loved this and will be coming back again in the near future. 10/10 would recommend to anybody.