Is it alright to answer college supplement essays straight-up?

I’ve been working on my Yale application, but I’m not sure how to approach some of the essays. For example, I answered the Why Yale question in a pretty straightforward manner-- I pretty much just gave a sincere answer about why Yale appeals to me, but reading around the internet some people are writing haikus and other crazy things for supplements. Do you think that it would reflect upon me negatively if my answers are somewhat straightforward but well-written and sincere?

No, I don’t think it will reflect negatively. You should answer in a way that feels natural to you. A little sincerity among all those goofy haikus might be a breath of fresh air for the application reader. Don’t second guess your instincts.