Those images you linked to the end made all the difference! Seeing the the details up close really helped. You were able to hid so much depht and 3D to that picture, to the grass and to the flowers. Seriously, you're into something here. Mountains and the sky as you said were little lacking, but this is some good stuff you're cooking.
Have you thought trying some other ways/materials when painting, or perhaps combining them? Acrylics are good and all, but adding pencil or watercolors can help with the details.
Shadows and the sun rays in this one are really well done. One can sence the setting evening sun. Well done!