I love the small but not too easy puzzles. An extreme example is the Arrows puzzle of the WPC2011. It was only 2x2 and the number of possible positions of arrows around the grid is only 64. But the solving time was 2 or 3 minutes and only 50% of the participant solved it.
This week I will publish some small puzzles. But generally they will be harder than you expect, however, there is a natural limit of difficulty because of the limited size. Sometimes it took me a lot of time to gain 1 or 2 minutes more. Is it worth? Generally no, but sometimes I can create / discover a gem. :-)
The first one is a LITS.
Rules for LITS