Pumpkin Ale

Hi, I'm a newb to home brewing. I've made 2 batches of pumpkin ale based on a recipe from Midwest. I have a chemistry background and grew up in a restaurant so I can follow a recipe and keep things clean. Anyhow, I know adding in brown sugar can make it a "thinner" ale, but I also got a taste, a tang, if you will. Is that normal with pumpkins, especially using LME and partial mash? Is there a secret to making it creamier? Do I need to go to al grain? Oh, was using one step, and some stuff I rinsed quick, but not everything if I remember right.

Oh, my wife had crockpotted the pumpkin and she froze the punkin juice to use to cool the wort. Also has used ice in the first batch. Maybe picked up a strain of sumtin sumtin?