Adventure in boxed cake

I decided to make a cake for my boyfriend's birthday last week. I've never made any sort of cake before, and since I was short on time, I figure it would be better to make the boxed type rather than from scratch in case I were to mess it up. So I went and picked out a nice box of chocolate mix and some vanilla icing and some green drawing-icing. And more eggs, because I forgot that we still had two other containers of eggs from previous incidents of "oh this recipe calls for eggs, I don't have those right now." Obviously they made these for stupid people, which is great, since I don't know what I'm doing with cake. Dump all ingredients in bowl, mix. Grease pan, that's probably important, I'll do that too. I hope my oven likes me today, doesn't burn my cake... I've learned now that I set my oven slightly below what it says, and put the timer for possibly even less than the recommended time, and slowly add time on until it's done or it even the littlest burn becomes a screechy-fire-alarm problem. It's interesting cooking here. Stupid electric oven. But the cake came out fine. Granted it looked like a small hill rather than a nice flat sheet cake, but whatever. I waited to ice it, because that's what you do, right? I even waited longer than I really had patience for. Alas, even with my extra patience, I failed at icing it nicely. It just picked up all the crumbs and distributed them even thru the icing, making it look as though there were sprinkles on my cake. Sigh. Then the "happy birthday!" Turns out that's hard too and sorta blobbed at points... it it's the thought that counts when making a surprise cake for someone, so it really doesn't matter, especially since my boyfriend will eat just about anything.
Cake:

I don't know, I think it looks edible at the least. I thought it tasted fine. For boxed cake.