Winter: The atmosphere feels like winter immediately. I like the ambient pads you use and the solo piano sounds beautiful but stark like the cold of winter. On the repeat of the A section, it makes a lot of sense layering the violin and I like the bell counterline. Then adding strings and brass gives the feeling like a snowfall that slowly accumulates overnight and before you know it, you have a full blanket covering the ground. Glockenspiel is always a classic winter instrument and I enjoy your melody layering with one on the final repeat.
Spring: I like the common melody and harmony, but also appreciate the variation that explores the extents of the minor key you are in. I really like your interpretation of spring since it is not the typical major key, happy-go-lucky depiction that a lot of people (myself included) have created. The emotions conveyed feel a little more like there is a determination feeling or like you are in the middle of a quest.
Summer: The brass melody layered with violin immediately gives a sense of warmness like a summer day. I like that you used the 8th note driving rhythm in both the spring and summer themes, but it feels more full here, which to me makes imagery of grass growing taller, thus making a nice realistic transition from spring to summer. I like that even though you are in a major key, that you still used the same borrowed chords from the parallel minor to keep the bVI-bVII-I cadence. The French horns at the end sound quite triumphant and are a nice touch to the end of the theme for summer.
Autumn: I notice a lot of similarities between this and the spring track. The choir is a very nice addition and gives a sense of finality. I’m curious which choir sample library you use?
Overall: I think your common underlying idea is very strong both melodically and harmonically which lends itself to sounding good when being reorchestrated and reimagined in different settings. These tracks are very strong and would work very well in an open-world type of game in which there might be long stretches of time without track variation and a need for music that does not sound repetitive. Thank you so much for sharing!