TD Trees, critiques need

[Ipsen]

Greetings, urgently needs help in creation trees, in TD-stile.

Here is that there is for current moment:

[JJ Naas]

The real test would be to see if they still looked like trees if they were some other colour than green.

Here's something similar, although these can be hardly counted as pixel art anymore:

http://g2.emag.cz/magazin/524/sshot-3.jpg

http://games.softpedia.com/screenshots/Close-Combat-A-Bridge-Too-Far_2.jpg

The shadows of the trees make a huge difference.

[7321551]

There's too much randomness here!

You have to break it down - what shape is a tree? Some shapes are harder than others, so let's say they're roughly conical. Then shade appropriately.
Noise dithered grass is unpleasant. Make up a pattern that can pass for clusters of grass & shallow slopes (light & dark patches).