Arguably the question with 1941 is not "how did this get made" but "how did this go so wrong?"
Steven Spielberg directs a story by Bob Zemeckis & Bob Gale featuring a cast of iconic comic actors from SNL, SCTV, and Animal House ... and it's more than 2 hours of noise, jaw-dropping racist stereotypes, thigh fetish shots, explosions, and so much screaming that it often feels like they inserted a supercut right into the narrative.
Added bonus of viewing is that you can see the building blocks of story and action sequences that led to considerably better films such as Raiders of the Lost Ark and Back to The Future. Treat Williams is essentially the proto-Biff, his entire "I hate eggs" arc will seem remarkably familiar. (Treat Williams' character is, however, considerably and disturbingly more rapey.)
Did I mention that John Milius is a co-writer and producer? Because if you're looking for a light comic touch, look no further than the guy behind Conan, Magnum Force, and Apocalypse Now.
