i think one thing that K-dramas get right is the heartfluttering moments and the tooth rotting fluff, and 'Mr. Heart' wasn't an exception! It's your typical college romance BL with not too deep of a storyline tbh which did eventually make the finale less satisfying for me. Also because each episodes is only 10-15 mins. long and the series only has 8 episodes the writers really had to make sure thye used each minute well to showcase the main couple. This was well done imo, but i would've loved to see more of Sangha's own life (his family, friends etc.) besides Just Jin Won TM. Especially the loanshark storyline could've been fleshed out better and more cohesive because it kind of came out of nowhere.

Overall, I really liked the production of the series and the small cast was great! There were a lot of cute moments between the two leads and the side characters were very funny! I do think they overused the weird 'French' (?) music. Sometimes i think it wasn't necessary to use so much background music, or at least if they had to use background music use a different tune? maybe some peaceful piano?
Anyway, it was a fun low-stakes watch and i would recommend it as a beginner BL series :)