An excellent detective game with a genuinely compelling mystery - I managed to make the connection with the birthday and the lottery ticket, but was too nervous to make an accusation based on just that! There's enough information that cross-checking testimonies and trying to work out motives and lies is really fun :)
Also, having quickly scrolled through your replies to some other comments in here, I absolutely love the "you are Bob" theory and wholeheartedly subscribe to it!