Introducing the 1's and 2's -- I guess my fairly easy night shift job gave me yet another chance to come up with another idea that I already implemented today. The 1's and 2's -- these are tile types that change when you pass over them. The 2 changes to a 1 (and continues allowing you path access), but the next time the 1's change to a blank tile, therefore blocking your path.
This provides an opportunity for strategic puzzles where how many times you travel past these tile types will matter. Good luck! P.S. I hope to make even more Featured Levels (additional levels) that become a challenge for these tile types.
