Thank you very much for your feedback (and for the compliment on the illustrations too) !
It is true indeed that a snare sound or some drum variations on top of the hi-hats on those tracks could help bringing more energy in those parts (I should look more into what constitutes a great drum section since I have been more focused on the melodic aspect of music untilnow, could be a great idea for my future compositions).
Anyway thanks for listening and for your comment !