Someone has posted it in steam, but I'll do it here anyway to make sure NN know the problem.
This VN uses high CPU/GPU usage, and any simple VNs like this shouldn't be used this much usage. According to the steam users there, this is most likely because the FPS problems.
Pict related is what I have in my laptop when I play the VN (This is using intel integrated gpu btw).
Edited: Might as well comparing this to NN's another work, Sanoba Witch.