Even if you somehow knew nothing about these movies, you could probably guess from watching them that the first one was a surprise hit, because the production values skyrocketed from the first to the second. There were some things about the first movie that must have been that way because of compromises (the future world was kind of boring, the background music wasn't very good) while the second movie was probably closer to what they originally envisioned.
On the other hand, the ending of the second movie wasn't as good, because it was too reliant on special effects, and the feeling you get there was, they spent so much on special effects for the ending (there was, for example, a weird alien that splits and combines from two other aliens, and robots Bill and Ted made from hardware store junk) that they didn't want to cut anything, so the pacing slowed.
Both had their share of funny parts, though. Some scenes from the first movie were drilled into my generation's brain during commercials, but that was so long ago that I managed to forget "royal ugly dudes" and laugh at it again.

