I have no idea what that mostly gold thing is above the door(looked it up. That's your monster spawner?).
It is indeed the monster spawner. It will probably be revised in the future since mob spawners now have the useful function of showing what it spawns in the center.
The bark left of the birch looks a lot like planks to me.
It's a more "cartoony" version of some trunks that trees can have(where bark tends to grow as planks almost). I used to peel them off trees as a kid all the time.
Some of the wool have fancy designs/gold on them, and the others don't 
?
The original idea was to give different wools different looks. Red and purple got fancy designs since they, to me, are royal colors and mostly used for carpets.
Your flint doesn't look like it could possibly be used to make those flawless arrows.
True, my first instict when I drew an arrow is to make a typical arrow, not one of flint. I'm not sure if I could make the look of my flint that small though, but I will try.
Your tools look very nice, but I like to think of the gold tools as the overly ornate tools, which is a personal thing I guess, but they aren't as durable as iron, so I feel they should at least have looks going for them. Then your diamond tools are overly ornate, which I don't argue with, they just have a lot of gold on them, which only cements in my mind that the gold should be ornate.
This was something I did on purpose. Gold tools are useless, especially compared to iron/diamond tools, and I don't even think deserve a fanciful design. If a tool deserves to get a fancy design, shouldn't it be the ones that are hardest to make, and are the most useful? As for the gold in it, what can I say? I don't feel like it'd be in the best interest of the icons to limit them directly to what they are crafted from. Sometimes aesthetics > realistic. Realistically you wouldn't be able to make any tools strictly from wood and stone since you'd need to craft them together somehow. Thus my stone tools got rope/string! I felt the diamond tools benefited from being two-tone, especially when you consider how close in color they are to iron tools. I put a lot of importance on blocks/icons being instantly recognizable, so I've made many adjustments to blocks and icons to hopefully achieve that.
Then in seeming contradiction to that, your watch is far too ornate for my tastes, feeling like it should be on display somewhere instead of in an adventurers pocket, and also clashing with the compass, which is crafted in a similar manner.
But the watch DOES have a very useful purpose compared to the tools. So I don't think it's unfair that the watch is more ornate than the tools who no one uses. Also, the compass has been a part of the game for a long time while the watch is fairly recent, so how I approach two icons between 4 months or so probably has a lot to do with it. Though you also have to take into consideration the constraints placed into the game. The content of the watch and compass are generated via code in the game. So the perspective and the size of the watch and compass are pretty much forced onto me. The watch was the hardest because the center of the watch occupied a huge portion of the actual work space, so I had little room to actually do my own thing.
But I do want you to know that it does look very nice, I hope you finish it, and the parts I disagree with are just my personal tastes. Also I apologize for this ridiculously long post, I hope you have found it helpful. If not, I apologize again for wasting your time.
I do appreciate all criticism and it does not shy me away from working on it. I can especially benefit from even those things I can't agree with because in the end I will have alternative graphics for users to pick and choose that will hopefully make more people happy.
