As a one season effort in 1977, Filmation's, "The Space Sentinels", (originally called "The Young Sentinentals" because the characters were immortal), was actually very enjoyable. It made quite a bit of buzz around the ASU campus that year.
Unfortunately, the show was not renewed for a second season, but it left a lasting impression on many who saw it. The superhero characters had good chemistry and some interesting story ideas made the show unique on Saturday mornings.
When Mattel was shopping around for a studio to bring their toyline to a SatAM animated show - Filmation quickly adapted the "Space Sentinental" storyboard to new characters with a much more developed world as a setting for new stories and adventures.
I always considered Prince Adam/He-Man a knockoff of Hercules, but side by side I think enough effort was applied to make the characters look different. Thematically, He-Man and Hercules occupy the same space, but "He-Man and the Masters of the Universe" have a whole new amazing world in which to engage audiences - quite diffrernt from the more limited pallet surrounding "The Space Sentinels".
My favorite episode of "The Young Sentinels" envolves Anubis, the Egyptian ruler of the underworld. I like an antagonist with a quirky demeanor and Anubis seems strangely interested in the Space Sentinels rather than simply wanting to destroy them.
Let me know your thoughts on this episode and do you see the makings of a future He-Man in this version of Hercules?