The best games are often the ones built from the simplest systems. Tetris is an obvious example; five basic shapes and the imperative to fit them together without any gaps. The rules of chess can be grasped quickly, but the possibilities are close to endless. And while it’s only really a game in name only, Conway’s Game of Life can generate impressive, complex patterns from just four rules.
Oh Hi (or 0h h1; it doesn’t seem entirely certain) is the latest game in this sort of vein that I’ve come across, and it’s quite glorious. Created by Martin Kool of Q42, and based on an existing logic puzzle called Takuzu (and sometimes known as Binairo), it’s a browser-based HTML5 puzzle that’s a bit like Sudoku, a bit like Threes and a bit like that good old Windows staple, Minesweeper, and it’s eaten into a quite frightful amount of my time over the last couple of days.
All you have to do is fill a grid with orange or blue squares. There are a few already in place to start you off, and three rules to observe:
- You can’t have more than two squares of the same colour together
- No two rows or columns can be identical
- Each row/column must have the same number of red and blue squares
Easy! It starts you off gently with a 4×4 grid that’s good for introducing you to the rules but won’t tax you for especially long, then there’s a 6×6, 8×8 and finally a 10×10 grid to really test you. Once you understand the rules then you shouldn’t have too many problems with the 6×6, but if you get stuck there’s always a button you can press that’ll help you find your next move, while reminding you which rule you’ll be observing while you make it. It’s a great way of helping Oh Hi’s little system bed into your brain.
Even once you have all the rules down pat you’ll still find yourself needing the help button every now and then, because once you have the grid half-filled and all the obvious opportunities start to dry up, you’ll invariably find yourself staring at the grid, swearing that there aren’t any legal moves left.
If you follow the rules then you won’t make a mistake (if you do, the little eye-shaped help icon will start to bounce up and down to alert you to the fact and enabling you to undo to the point where you went wrong), but with so many squares to track it’s easy to get stricken with the sort of selective blindness that lets you overlook something for minutes at a time.
What’s especially lovely about Oh Hi is that the system just works. Apply the three simple rules and you’ll reach the only possible solution, every time. It’s pure and elegant in its construction – something that’s reflected in its minimal and effective flat graphics – and, once it gets its hooks into you, appallingly compelling. If you have something really important that needs doing then I urge you to stay well away.