Is it a disagreeable alcohol flavor, or just extra-strong regular-beer flavor? Would you describe it as solvent-like? Like acetone or lacquer thinner? Rose, bitter, chemical taste? If any of these, you may have other alcohol types in there than the alcohol usually found in beer (ethanol).
I have Dr. Lee Janson's book called Brew Chem 101, and in its section on identifying and avoiding off-flavors this is specifically mentioned. There are many combinations of alcohol molecules, many are produced during the fermentation process and subsequently used up again (broken back down into ethanol and more beer tastes). To quote the book a bit:
Fermentation that's too fast or too strong or uses the wrong starting material (say, amino acids instead of sugars) can overload the normal ethanol-producing pathway, resulting in undesired products.
Bottom line, to avoid these other alcohols from being formed, he says to choose the yeast strain carefully for the recipe (probably not your problem since you're using a kit), control amino acid content by proper recipe formulation (once again, you're using a kit), maintain sterile brewing conditions and control fermentation temperatures. So as long as you sanitized well, the most likely cause of other alcohols is too high fermentation temps.
I'm the type of geek who likes to dig down to the root of the problem and understand what exactly went wrong, so I can avoid it next time. Hopefully this info helps you make better beer next time if it applies to you.