I compiled these drawings considering their composition. But they are meant to represent a month in a year :)

The design concepts are as follows:
Jan - Pixie Forest (Day)
Feb - Rosy Mountains
March - Fire Tree creek
April - Bone Volcano
May - Cherry Blossom Field
June - Overgrown Ancient Partheon
July - Underwater Dome
August - Tangerine Desert
September - Pixie Forest (Night)
October - Autumn Farm Fields
November - Neon Jungle (Avatar Fan Art)
December - Icy Cave

Hope to improve more in Pixel Art in the future, but I will start focusing on 3D now. Happy Holidays!