The acting was fine or whatever. The plot and ideology behind it are twisted and depraved. At root, Will Smith's character puts himself in the place of God, controlling who is going to be allowed to live or have a better life, and using parts of his body and life to do so, ultimately with the goal of suicide in donating his heart after killing himself--or rather, allowing a jellyfish to do so, even though technically that jellyfish would not be able to do that in the bathtub of fresh water (just in case a suicidal viewer decides to do that or a psychopath thinks of murdering someone in that way).
So in order to justify killing himself and making himself feel better for his carelessness with phone or such causing a car accident, he plays God, and what the movie maybe hopes will pass as great courage and selfless heroism, is actually always and only self-serving means for Smith's character to try to make himself feel better for the outcome of accident, lives taken. And somehow, then, suicide all along his goal as he could not cope with living with himself for his human error, tragic as it was, suicide is to be justified and acceptable because he chose whom to help by gradually donating parts of himself--body and his house.
It's not way to live, and no way to die, either one. Self-serving from the start and in the end although trying to deceive himself and others in the drama as well as viewers, that somehow he is a sacrificial hero, a god-figure, yet somehow really just a mentally depraved and twisted, very depressed person without courage to forgive himself and live out his life like the rest of us are supposed to do and do so with real courage, even if we accomplish nothing other than show the strength and endurance to keep going until God chooses.
Of course, this movie is not based on God even though it steals God's thunder, so to speak, and tries to mimic some sort of Christ figure in the character Will Smith plays. Regret that I watched it, but I did not read reviews first other than saw all the nearly five stars on Amazon. And during the film, it was contorted enough I could not see where it was going until toward the demented, depressing, twisted end.