Balance: 10/10 - I liked Standard and Draft. If you card is a rare, I will be asking my self, "Self, if I was on my way to a tournament, and I was to build a deck to support this card, would I have a reasonable chance of winning?" If the answer is "no," how much would I not want to? If the answer is "yes" how much do I want to? (since it could unbalance the game).
If the card is a uncommon or common, I will be thinking about what pick I would choose it in draft, and whether or not having lots of it would unbalance the draft. (I will also think about it in constructed, but as a support card.)
I will also ask myself if your card would unbalance any of the older formats, but will care less about that answer.
Finally, if its clear your card is a casual card, I will TRY and be understanding, but I am a terrible casual player, and really have no grasp of the format.
Flavour: 10/10 - I will probably be more lenient in this category. The main questions will be: "Did I like the Flavour or not?," "How much does the art fit?" But I will try not to be too harsh. Bad art>no art. Think
Goblin Offensive flavor.
Creativity: 5/5 - "Has this been done before?" "How 'new' is it?" Think
Doran, the Siege Tower's ability.
Quality: 5/5 - "Does this card (need/should not have) flavour text?" Also, I will be taking off -.25 for every 'small' error I find, and -.5 for every 'large' error. If your card does not work in the current comp rules, expect a -1 here. Make sure you have a text card, and your text card lines up with the render.