Tristis is logic game with a twist of addition [iPhone]

Tristis is a logic game that throws in a little mathematics. You are given a five by five grid that contains a handful of numbers, with another group of numbers on the right. The numbers in the square grid are on grey chips that are completely static and therefore cannot move. The numbers outside the grid are on purple chips and can be moved inside the square grid. The goal of the game, which is much more difficult than you would think, is to fill the grid using purple chips to ensure that all vertical rows, horizontal rows, and diagonals have a sum of 65. Tristis seems to fall in the Sudoku genre of games, but the game is a bit more like Zengaku, which I reviewed last week. There are actually 4 different levels of difficulty (beginner, easy, medium, hard), which I took full advantage of until getting the hand of it. In reality, there is some challenge with all the guessing and checking involved in the game, so be patient. Just to add, I did have a few problems with screens overlapping each other at some points in the app, but it never occurred in the actual live game. My guess is that it’s just a bug.