Let's say that over 3 years, you average 2 hours a day. That'll be 365 days x 3 years x 2 hours = 2190
And then 1000 players download your game and beat it. 1000 players x 5 hours = 5000 hours.
Therefore, for your 2190 hours invested, you created something that provided 5000 hours of entertainment.
Not too bad, depending on how you look at it.