Random impressions:
- The "Home", "Sign In" and "Sign Up" links at the top of the main page don't go anywhere. The "Home" link is unnecessary. The "Sign In" and "Sign Up" links should go to anchor tags at the sign in and sign up forms.
- The Birthdate drop down menus are broken for me on the sign up form. I only see a vertical scroll bar when I select the day and month, and I have both vertical and horizontal scroll bars when I select the year.
- The What I Want page should initially has nothing selected in each box. I think each option should start populated with "Anything". That way if I don't care about pets one way or another, I don't have to waste a few clicks setting it. Or do I need to actually change an option from "Choose Option" to "Anything"? It's unclear.
- When I finally select everything in the "What I Want" page, the red text "Please choose an option for each field." doesn't go away. Did I not select everything well enough?
- At the bottom of the "What I Want" page you have every percentage listed from 16/16 to 0/16. Is that really necessary?
- The Profile page has square images on top of other users, but when I resize my browser window too small horizontally they're squished into rectangles. In addition, those images are huge! It took a few seconds for them to load the first time I visited the page. They should probably be resized. Also, perhaps profile images should be stored as jpegs instead of pngs?
- Search form, perhaps it should be pre-populated with the options that I chose on the "What I Want" page? And again, even when I have every option selected, it still says "Please choose an option for each field."
- On someone's profile, under their Personality Type, there's a yellow circle that on mouseover says "They don't have your preferred personality type, but keep reading!". What? When did I specify a preferred personality type?
On a whole, it looks well done for a MVP. Some other people have criticized the lack of design, but personally, I like the minimalist look. These are just first impressions, I hope they help.
FYI, I'm using Firefox 29.0 on Linux.