It’s enjoyable, but the writers basically had a really good idea for the start of a movie and then no idea of how it should develop from there.

Somehow that puts me in mind of Explorers (1985).

the alien comedy monolog was hilarious to me as a kid, but I haven't watched Explorers in probably about 30 years.

Seems fair.

I recall Paul Rubens, jokes about Twisted Sister, morphing spaceships, time travel, Fort Lauderdale Florida (which seemed impossibly alien to this midwesterner), and a lot of pop culture references.