To escape from this 3D world, use the arrow keys to walk around. There are 4 letters hidden, each in its own letter room. The 4 letter rooms can be found by exploring the maze. When in the correct order, these 4 letters will make a word. When you have found this word, enter the Letter Room, click on the text that says 'letter room', and enter the word/code. A door will open that leads to the party room. When you enter the party room (which is next to the home), you can celebrate!
Happy Birthday to @hellocato