Smoothly implemented closed house crime story. You assemble all the clues, then work out the alibis. The artificiality of the setup is made up for by the neatness of the solution and pleasingly bizarre but self consistent plot. The format lends itself to serialisation.
The in-game chalkboard system is good at collating all the clues for you, but a having a paper and pen handy is recommended for putting it all together.