Only the houses are dull.. i have dull ocean water if you want? :P
i think the placement od the 2houses/lab is good. Though the short amount of small trees, makes it look abnormal, need little more. Wild grass?
I know your trying to portray a pokégarden behind the lab, i think i got a tile that might work, its like the wild grass for r/b/y ect. but you can you for like tall, not wil grass or something.
The gate buildings are out of place, personly I dont like when they are used like this. (though the bottom one, I would accept like on a special route)
A mart really? its your map, though I dont see a reason.