Green blocks are the goal in Happy Blocks. There will be yellow, red, and purple blocks, and you must turn the yellow ones into green by placing the green blocks in the right way; the red and purple ones can't be turned into green and will block your way. In your green blocks, there will be directional arrows, which means it will turn the surrounding blocks into green based on that directions. Sounds complicated, but it will become clear once you play the game. Have fun!