Ryu, these are pretty nice! Thinking of how hard is to paint on a real canvas, I see you handle the medium pretty well!
I really like how the lamp painting palette gives it almost a pixel-esque feeling. Also, very nice color play in the "two hearts" picture. The only problem I have here is with the bananas -- as they seems kind of lost among the warm red colors of the cloth which makes up the background; and the girl -- some features, esp. the face, seem to be neglected -- I understand, however, it has something to do with the brush size as well as just its sketchy character.
Keep it up!