The idea of the show is very simple and given how short the show is, they could've made it much simpler and more satisfying to watch. It felt like the main conflict could've been very easily resolved if the main character just behaved reasonably.
Because of how short it is, the relationship between the main characters developed very fast. I personally liked their chemistry and found their interactions pretty cute, yet a bit awkward at times, but it didn't take away from their relationship.

Spoiler:
Tbh, the show could've ended without the last episode. The moment Min Hyun agreed to give Jun Ho his blood it should've been the end. Jun Ho's stubborness was completely irrational and while I understand that he was afraid of killing Min Hyun, there had to be a solution to make sure he doesn't hurt him.
It's a lot of unnecessary angst, but there's a lot of cuteness as well. Mostly because of how innocent Min Hyun is with his feelings. It's just adorable. The ending didn't feel as heartbreaking as it was probably intended. It just felt stupid.