As someone who has lived in this boring form world for far too long, I never thought I would live to see the day when someone would come along and completely break down barriers, cause a paradigm shift and rewrite the book on accessible and innovative forms... until now.
Some of my favourite things from a usability perspective you've added I think the likes of Google and Facebook should borrow to help drive up their conversion rates.
The inability to focus one side of the cube - This is brilliant. I love how I try and fill out the fields, but I have to wait for the cube face to roll back around again so I can quickly fill out another field. It took me about 6 minutes to fill out your form which I think is much better than other forms I've used that have taken me 30 seconds (jokes on them). I think keeping people on the signup page longer will definitely help lower your bounce rate.
The small unreadable labels - Why has nobody else thought of this? Everyone is concerned with making their forms nice and big, helpful contextual labels and other things to make the process of filling out a form easier (or so they say). I had to zoom in a couple of times to read the labels, but the speed of the cube means my eyes can't properly focus: good job.
The speed of the cube - When I first saw the title, I immediately thought, I bet they made the cube spin really slow and I'll be able to see the form labels and inputs clearly, how wrong I was. The speed of the cube is fast, but it's not too fast. It's just fast enough to make it hard for your eyes to focus and things to blur, but not too fast. I think the speed of the cube makes your site appear faster.
But, alas, there are some issues with your form:
That font isn't very appealing - I suggest trying out a nicer font, Comic Sans MS Bold would probably be my first choice. It's readable and it would make the spinning cube even more fun.
The green isn't bright enough - Sorry to say it, but that green just isn't bright enough. You could take it up quite a few shades lighter to appear more modern.
The submit button isn't centered - I think the submit button side of the cube should be centered. At the moment the submit button is aligned to the left and the text within the button isn't centered either. This is bad for accessibility and making those two small tweaks will make it definitely better. Consider making the button work with the design a little more by making it black or white. Grey tends to look very dated.
Lack of warmth or character - I think the lack of animated GIF's is really impacting the form, but not only that, I looked in the source and did not see one single instance of the
<marquee> tag. Aesthetically it is a little TOO static for my liking, some movement in there could make it more fun (in combination with font change, of course).
Lack of validation - As far as I could tell, your form lacks validation and or validation messages. A form without validation is a usability nightmare, if possible, you should consider using the
<marquee> tag for the validation messages to make them appear more friendly and less passive-aggressive like other forms I have encountered over the years.
The social security number label is too long - The label is wider than the others, you could try right aligning the labels or perhaps putting a line break on this text to make the lines a little shorter and more readable.
In Google Chrome (latest) on Mac OS the select dropdown is broken - The label text is appearing above the label.
Again in Google Chrome (latest) on Mac OS the heading on the legal info page is broken - The I is actually being cut-off, so I can only really see, "mportant legal information!!!"
Too many exclamation marks - Why are you shouting on the legal terms page? One, maximum, two exclamation marks. You know the rules? Don't spoil a great design with too many exclamation marks.
Overall great design, but an even better troll. This is probably one of the best troll questions I have ever read, even rivaling some of the questions I've come across on Yahoo! Answers, so good on you.