Nice colors. Could use some work. Even though I think you weren't trying to be exactly like the real version, the eyes could look better if you drew them a different shape. I like how there is at least shading, but there is too much on the Evee. Instead of having this much shading, I would suggest having more contrast: lighter in the light parts and darker in the shaded parts. To make it look more realistic, there could be more detail in the Eevee's fur and in the background. The shading on the "grass" looks a bit random; have shadow right below the Eevee but not all around it. If you drew in something else besides grass, it would be great (nothing too fancy, though, maybe a few flowers). Instead of there being a random sparkle, I would have it: a) not there at all, or b) from something sparkly, like dew on grass. Overall, you did fine.
I'v never done a critique before so this might be short but. I give it a full on vision, the shading is done very smoothly, and its accurate with the lighting. also the body is drawn well (like the head isn't to big or anything) 4 and a half on originality because while the picture is very good, its still kinda just an eevee. (though thats not bad, eevees are cute) the technique is a full because the colors, lighting, and position of the eevee make a very balanced atmosphere. and the impact is full because the picture is very nice to look at, and it gives a nice calm feeling.