Wow, this is very nice. I like it very much That tree is actually REALLY good, better than me any day lol
Alrighty, on to business~
Vision: Very bliss and soothing thoughts come to mind when I saw this. I wish I could find a nice grassy field and nap with bathing in the warm sunset like Tails is.
Originality: You know what's funny? I often see a lot of Sonic fan artists drawing Tails relaxing in one way or another whereas ironically to Sonic TEAM, he is such a busybody in the video games. It's always nice to see a different of a character ^_^ Big plus on your side for that~!
Technique: The soft brushing really adds to that 'dreaming' feeling in this picture and the colours couldn't be more correct. You have a good sense of light-sourcing. A tip would be to make the grass and the leaves of the tree have an orange tint since the sky has one. It would add A LOT more warmth to the picture.
Impact: Nevertheless. I really like this picture, it makes me want to have a break at whatever I'm doing right now and soak in the sun rays
I also fail at trees don't worry. XD I love the colouring! Sorry if I am mean but try working out where the light source is and where the shadows are unless you intended to have the light source in front of the picture. Keep trying! It looks good so far.