This page introduces a simple concept of “ends”, intended to provide a framework to improve your general speed and ease of gameplay.
An “end” is what I call any tile that must be stepped on last, because there is only one path that leads to that tile and no paths back once you have gone to that tile. The simplest example can be found in Easy – 3:
The circled square is an “end”; it must be completed last, as there is only one tile leading to it (and you cannot go back on that one tile). If you decide to step on that tile before the end, you get stuck (as below).
How is this useful for gameplay? A rule: never create 2 (or more) ends. Any time you have 2 or more ends, you know that you cannot complete the level. With this knowledge, you can use the process of elimination to get rid of certain potential moves, making it easier to find the right move. For example, in the below situation, you have two ends, and are already stuck, so you can rule out this path:
The one block sticking out, as above, is the easiest type of end to recognize. There are some other formations that are a bit harder to recognize as ends. One example below:
In the above, the entire 6-block section is an end – there’s no way to clear this level from the position shown above.
One formation I want to point out in particular is the below, where you have one orphan yellow tile sticking out, but attached to a red tile; this pops up very frequently. This is not an end (by itself), because you can step to the yellow tile and step back. Recognizing this, you can make it a rule of thumb to leave these formations around, treating it as if the two-tile formation is a single yellow tile where the red tile is.
The circled, as above, will not become an end when you take the path starting from the left, while the left tile will become an end if you move right first. The solution? Move left.
There are a few levels that can be solved entirely by identifying ends and using a process of elimination. The below is one example: it’s a lot easier once you figure out where the end is:
When you get really good at identifying ends, you can make observations as follows: in the below screenshot, after only two moves, I already know the player is stuck. One end has to be created as the player moves from the left through the top circle (or you create the end on the left) and the other end is created at the bottom. By the way, since there’s no way to clear all the tiles at the bottom in one go, that has to be the end – a pretty big key to solving this level.
This is sort of a subset of the above. In brief, there are certain formations that simply cannot be cleared. Avoid these at all times (and undo or reset if you ever see one). One of the most common ones is the orphaned red tile with only one yellow tile leading to it:
Next: Rules of Thumb