Well... you missed the main topic "Inversion", thought. Better keep an eye on that next time. The wildcards (like can be played on mobile) are only an extra bonus, which you optionally can choose as a limitation. But, the game is fun for a while.
I only saw the food on the map, so it's kind of hard to know where to go and if you already ate it. You implemented the animation of the snakes quite well. everything ran quite fluently. I would like some sound and music too...