The number by the items you collect affects which ending you get.
If you have eight of items ending in 1, you get a first layer ending
If you have eight of items ending in 2, you get a second layer ending, etc.
You collect items of higher layers by exploring further into areas.
The Guide page at the top may help you find more of the high-layer items as well.
(By the way, the characters name is W.T.)