Here's the thin plot in 10 lines. A weak film that had potential.
PLOT
Elderly antique shop owner, Jesus, unknowingly owns an ancient elixir of eternal life (in the form of a robotic bug), and accidentally 'drinks' it. Meanwhile the owner of the elixir's rule book, a bitter and dying elderly man, obsessively tracks down and purchases the elixir via his able-bodied enforcer nephew (whom resentfully complies in wait of death inheritance). Jesus feels invigorated by this new energy but discovers that sustaining it requires human blood to supplement the elixir topups - without which his flesh rots. The dying man angrily learns that Jesus sold him merely an outer container and kept the elixir himself, so has the nephew enforcer murder him. Jesus returns to life intent on acquiring the rulebook, but the old man reveals he has eaten the pages, and then tries to murder (?) Jesus, who is saved by a violent interception from his (mostly roleless) granddaughter. The nephew finishes his injured uncle, securing the will. He confronts Jesus on a rooftop who wrestles them both off the edge, killing only the enforcer. Jesus exclaims he didn't ever care for eternal life, smashes the elixir, and dies a natural death later.
REVIEW
A great topic - concerning the value of eternal life - which stems all the way back to the Gilgamesh myth. The conceptualised fear of death is perhaps the biggest component in what separates us from the animals, and arguably the birth point to many of mankind's problems. Naturally, you may think there is much tasty and nutritious story to be juiced from such a big topic. So what went wrong? I think two things.
Firstly, the topic wasn't explored in enough depth or detail. Instead, a kind of cartoon argument was presented, stripping all richness of a meaningful subject matter down to a short series of uninteresting, unoriginal conflicts.
Secondly, the fact that Jesus didn't even really care about living forever in the first place meant that there was virtually no character arc - barely any meaning - to be deduced from our protagonist conduit. What should have been a cautionary tale about Jesus's desire to live forever was instead just an accidental journey that involved merely a fun moment of youthful invigoration.
Instead, if initial stakes had been improved, there could have been a better platform for drama. For example, if Jesus was dying but only his skill X enable to protect his endangered love one(s), so chooses to artificially stay alive, and thus begins a slippery slope of toying with nature. This would have at least set the stage for a dilemma: toying with nature for an ethical reason, and the consequences that follow. Then enter in the tempting benefits of immortality and so on.