Hmm, it's a weird conceit playing both main characters, but if anyone can pull it off, De Niro can!
And he actually does.
The film at large, however, is pretty clunky. Not quite "amateur hour," though it sometimes veers that way.
Overall, though, I enjoyed it quite a bit.
Has all the usual "Godfathery" vibes you've come to expect from such a vehicle, so if that's your thing, you'll love this thing, too!