The Spaceballs movie was full of screwball humor and some fairly cheesy jokes, but it worked, because of good acting, sharp delivery, and solid comedic timing. None of those qualities are present in the series. The first two episodes try to recreate the movie, featuring the same plot, the same jokes, and even some of the same actors, but it's just not funny. The old actors seem to be going through the motions, and the new actors give near-deadpan performances. They don't bring anything new to the table or even try to recreate the performances of their predecessors.
Later episodes devolve into half-hearted parodies of popular films laden with awful writing and terrible jokes. There's a slight chuckle here and there, but it's not worth wading through the corny and often painful one-liners. If there's anything this series does well, it's highlighting how funny the original movie actually was. Save your time and go watch the movie again.