If the game freezes, just click inside it (games can get unresponsive if you click elsewhere on the page).
It a simple defense game. In this game you need to operate a snake with mouse for 2 purposes:
1. Let the snake alive
2. Kill the zombies to protect the treasures
The main thing to note is to operate snake carefully. It should not collide with walls.
You will find some more tips in the game.