Thank you for sharing your pieces. "Prelude", "Caves" and "A New Dawn" have at times a rather minimalistic feel, as figures are seemingly repeated, but slowly evolve. All four pieces remind me of the music in some point-and-click adventures, which probably has a bit to do with the software you have used, but also with the style that pervades all four pieces. This also makes the four movements a coherent whole.
If you want to introduce more tension, you could modulate to other keys or use some chromaticism. (Especially in "Caves" and "Forest Leaves", there are some opportunities for increasing tension this way!) Originally, chromaticism means colouring the music, because the slightly altered notes were perceived not as total change, but an altered colour of the original. So, colour your music At times, I even expected something like that, but the score proved me wrong …
Also, there are some very interesting piano soundfonts out there (like Yamaha Grand C5, Salamander etc.) that would fit your music very well.
Looking forward to more music from you!