I mean not every finished game needs a definite ending, might also just mean completion in a sense of the world encapturing everything that the dev wanted to include (which is the case here). It has quite some content, going in different directions. The systems he introduced (basement at home, bar job, whore house etc.) could be extended but as they are currently work pretty well with the rest of the game. And he clearly seems more interested to work on his next game so I'd say this is one of the better cases in which a dev calls a game completed and ready for sale, you don't often have this here in this forum (if he was in it for the money he would just drag it out to infinity and beyond).