I'm not sure I get it.
It's a rather beautifully presented story -- my last encounter with Undum had also been a rather pretty presentation; it is perhaps a strength of the system. The premise is that you are reading the last will and testament of a man, ER Milhouse, who made his money mining in the Congo. The narration, therefore, is in Mr Milhouse's voice, with the player directing his attention this way or that, until the final bequests.
I'm afraid that I found that voice a little opaque. The most entertaining wills tend to be concise, incisive and spiteful; contrariwise, Mr Milhouse has a tendency to ramble. It made the writing seem rather too opaque. Granted, there would be not much of a game if he did not ramble on so, but to me it felt a little too much like slicing through a black pudding with chopsticks.
It appears at first glance that the object of the game is to maximise one's inheritance, perhaps by "reminding" Mr Milhouse of this or that old reason why more should come your way. However, it would appear that the numbers are far too random for your manipulation to have any significant effect (beyond stealing the inheritance of your fellow heirs, should you be fortunate enough to be able to pay off the lawyers) so this is probably not it. The opacity of the gameplay, too, masks the direct effects of your choices, so the final results feel completely arbitrary. It has been pointed out, on the other hand, that perhaps the real point of the game is to let the player dig into the backstory, but again ... there is an endgame choice that hinges on the amount the player has coming to him at that point, and if the maximisation of one's inheritance is only a red herring, why close off an ending because of it?
So I'm not sure that the game really knows what it wants to be. Is it a story game in which we poke around to discover secrets, or is it a management game in which we twiddle the dials to increase our profits? There is almost certainly a way of wedding these two, though, and I suspect that the first step, and quite possibly the only necessary step, towards this is in clearing up the relationship between the various numbers and the player's decisions.
Congee with leftover roast duck, hardtack biscuits, and a thermos of hot rooibos.