On not including floor puzzles in the final game...

"Those types of floor puzzles are the hardest to develop and the most challenging to change after the fact, hence the absence of them in the final product. However, that idea of room connections is throughout the game at the room scale rather than floor scale. There are many secrets within 'gaps' in the map, behind oddly placed walls or rooms where the height doesn't seem to match those around it." - Holliday

"There are many instances in game development where at first, things don't turn out the way you speculate. When that happens, I try not to cling to that initial idea too much. For example, this is when I was working on The Legend of Zelda: A Link to the Past. At first, we were thinking about structuring the game with numerous parallel worlds. However, in order to establish the gameplay in the end, we decided that it would be better to narrow it down to two worlds: Light and Dark. I think game development involves much work where you never know unless you actually test it out." - Tanabe
On lack of an upgrade system/skill trees...

"Upgrades and skill trees aren't very Luigi. He is a reluctant hero who already has the skills and bravery needed to tackle any problem. Players are helping Luigi overcome his nervousness to expose his true talents. Cleaning, destroying and collecting are engaging, Zen experiences that everyone is familiar with since childhood. It is compelling ev...