That was interesting and different. I liked the Lupin III vibe and I think the graphics style was perfect for that kind of atmosphere. The music too was fitting and well made.
I can see the link between between gambling and lying and it works well in my opinion. Also the characters are well made and believable.
I think the dialogues were a little bit too long but you gave the possibility to speed the text or even skip it so it's fine.
I would've liked to control the investigation more, I had the felling of being more of a spectator then a player, but I think that you can improve the riddles a lot with more time for development.
Also the end was a bit cheesy with your accusation being turned against you but I think it works in the context of the game (I see a lot of Death Note vibes in it, where the antagonist outsmarts you every time).
Nice game though, I'm curious to see how you're going to develop it after the jam.