It's a awful tileset. Try setting the level in a normal tileset and re-submitting it. To be honest.. the tileset is so ugly that it makes any level look ugly.
If you are adamant about the tileset then I would say:
Detail: Reduce most of the ground detail to make the level look alot less cluttered. The tileset already does that for you

. Swamp grass errors and one of the seats have a screwed base.
Paths: They are pretty boring and standard. Make them thinner and more and move around more. Imagin flowing water ruttered out the paths and now it's dry [and somehow became flat.]
Houses: I don't know what houses are on Z.. I havn't played there. I would suggest not useing the hedging on the roof like that.. has no charm. If anthing have the brown as the base and, if you have the right tiles, cut odd shapes out of the roof and have hedge replace that. [if for some reason you need hedge up there].
The house stright ahead is alright. but the roof is again way to cluttered, specialy for this tileset.
Here is the level in a edited version.. but it's only idea based. It's not a set level I made for a finished product!! Just suggested ideas on this like the paths, swamp, lesser detailing [some areas I didn't detail at all, so ignore that].. and the man on the roof isn't for-real.
http://img.photobucket.com/albums/v172/Ducati/graal.png
p.s I dont have windows gfx so they dont show. wasn't deleted.
p.p.s I notice the big error on the bottem side of the chimney, south west house.