I think John Lithgow was the villain/alien if I remember correctly?
Correct! A villain-on-steroids I might add.

Buckaroo Banzai was always a cult hit...Peter Weller made it worth a watch.
To be honest the movie was rediscovered later in Sci-Fi conventions. Sadly, Buckaroo Banzai was a commercial failure when released.
Peter Weller was one of those actors able to turn an average movie into something wortwhile. And he has that amazing 'intense gaze'...
Note: He's also great in
Screamers (1996): it's still Sci-Fi but we're not in the 80 anymore...Great movie nonetheless.