Fair review below
Honestly, the graphics made it look like it was created by a 3-year old. At least try to put some effort into them. Trace pictures of real sprinklers or something, then color it grey with lighting or something.
Next, you used component buttons, which although they look nice, did not go well with anything else since they were so neat, and everything else plainly sucked.
This would work great as an engine for a real version, but in it's current state, its un-usable. A homeown also woulden't come to newgrounds or your Piczo website to use this. You would need to move it to a real website domain or something.
There is no animation at all. When you place an object on the screen it should have a short representation about how far the water would come out, or just a blue circle saying the diameter of its range.
Lastly, when you go in the begining, there should be a screen that the user could enter the dimentions of their garden in, so it would be more relavent. While I'm on this course, the grid needs reworked, and don't use blue for the background.
Basic points for improvement:
1) Graphic, graphic graphics
2) Basic animation/water diameter circle
3) Garden size window at begining
4) Better grid
5) More user freindly
6) Draw own buttons, so everything has the same style
7) DO NOT resubmit to newgrounds, it dosen't belong here. Try the forums
I know you already have, i saw the thread, just try it again with a better version
8) Make it a program, not an engine
9) Change background
And finally...
10) Add a print button, or a save button, add more features, add more sprinkelers, just add more THINGS to make it more useful to the home owner.
A fair review,
DFR