Ok, since this is your first map, I'll be a little easy on you.
Playability: Nice open places, abundant resources, signpost!!!!!, in short: a basic but very good free build map: a lot of playability: make your perfect castle here: a 4 is certainly a deserved number.
Balance: This is something else: I usually keep this one in line with the other votes, but now I will have to withdraw 1 point cause of the placing of the resources: it's just to easy: all the resources packed on eachother and only 1 great pack of them. E.g.: There is 1 massive pack of stone and next to that 1 massive pack of iron, also a great swamp ful of oil, if you could ever shoot an arrow in there, then I think they got the middle-age version of the atomic bomb!
Creativity: This is a basec map, not much creativity I saw here, just a map and some resources, however I liked the island with the oil on it (ok, the island could be a little smaller), but that doesn't give a reason for a 4 yet. don't worry, if you make more map, creativity will improve, so just keep making 'em, and if you ever want a tester. Ow well, It would be a 2,5, but I'll make it a 3.
Map Design: The weakest point of the map, as it is with all first maps: the rivers seem to stop immediately (I know you didn't notice, but you could use the space button sometimes, the waterfall is good, but not realistic (to much foam and no 'decorations'), no transition between 2 pieces, to massive resource 'blocks', no much difference in the terrain, I will have to give you a 2,5 for it, but I was all ready generous for creativity so I'll give you a two. But keep making maps, map design skills with grow with the amount of maps, don't let you be scared by a(n) ******* like me. But 1 hint: work on the map design harder, because the beauty of the map influences creativity and playability (unconscious however (or maybe not) but it still does).
Story/Instructions: Well, it doesn't mean that this is your first map that there shouldn't be a story, right? the absence of a story gets your rating down, so if you take the effort of making a story, your rating will be a higher, once again, if you ever need a sotry, mail me. But ow well, I'll have to give you a 1 for it.
Balance: revised: Overall socre without balance: 2,5, so I think it's justified to give a 3.
Overall: Make more maps, You're good at it, just keep on working on them, and ALWAYS make a story, even if it sucks, because you will still get a 2 then, instead of a 1. So I say: keep on working and you will be 1 of the best map makers around here.
[Edited on 10/16/09 @ 06:40 PM]