Don't like the choice of background because when it expands you get the dark top band (at least on my screen) and that draws my eye to it instead of the entry boxes.
You could word your text bit better too. I'd change it to something like the below:
This is a custom plugin paid for by a client, if you would like to include this plugin or have something similar made for your site please get in touch to discuss your requirements.
The only suggestion I'd make is if possible, have some kind of progress or stage indicator i.e. "Step 1 of 3". I've been designing surveys for a company for years, and respondents are always more likely to fill in a form if they know how long it will take them to complete. Here a quick 3 step process is a big selling point for the end client so I'd advertise that.