I made a guideline image using the easel and background so I could tell where to draw in the game. Also, if you look hard enough, you can see the lines from any color. My 77% was the second of 2 tries after I made the guideline image. ^-^
Spike was probably my favorite game to play for the tournament. At first it seemed like luck, but eventually you figure out there are some rules to the map gen (or possibly hand made maps?).
First off, there's the obvious tip of figuring out where the walls are so you don't hit them from two sides.
Starting with this:
You can already tell where two blocks are, which leaves only one path through:
One of the "rules" I was talking about was the fact that (I don't think) the end is ever in a straight line from the starting point. I don't think I've ever seen a case where there was only one turn either.
You may be tempted to do this:
But going off of the previously stated rule, you can assume those routes are blocked, which leaves only a few paths:
Now let's take an example of another level. In this level, you start 2 blocks away from the spawn. Since it would only take two turns (not counting turning on the starting point) to get the the end, we can assume there are blocks there. Typically (not always the case), the levels don't make you walk through the entire area, so two paths are immediately obvious here:
Which as you can see, one of the paths I assumed was correct and led to the end without any deaths:
One more rule I'd like to point out is that the pathways are never 2 tiles wide. Which can help you guess even more block locations/likely paths farther on.
The "rules" for Spike are only coming from my experiences, so they may not be true. However, the "rules" still seem to be accurate, so they definitely helped me get a good score. :D