Every poem from DDLC starting from Day Two( as that's where the poems start in the game), all the way to every Special Poem in order.

After falling through a portal, the turtles fall into the underground. lost and separated at different regions, they have to solve puzzles and meet monsters in order to pass and be reunited again... Will they survive intact and get together again? or will they stay separated like lost puzzles "TURTLES! STAY DETERMINED...." (image not mine, belongs to Glozy Blazey)