This is a little piece of a game that I'm not going to release anytime soon.
While I removed a large amount of content, there's also content that I simply blocked off.
In the Teaser, you will walk through some of the maps and be snatched off them just as it gets interesting.
You will be able to see some inaccessible parts behind walls which I think is really cool.
There is also commentary.
You will also get a Debug Device (you will need to find out which key activates it) that makes it possible to access all the teaser's content without having to modify the game.
You can see the items you collected by selecting Itembook from the escape menu. You can acquire the Item Guidebook by noclipping and talking to a glitched guy in the southeast corner of the map with the Mario trivia graphic, or by manually turning off the boolean ("Switch") #33. Both actions require Debug Device.

The game itself is mostly a walking simulator in the form you will see it, but you will also have a challenge section and you can even die.

I hope I'll get you hyped with my eloquence and architecture.

(This game requires no RTP, but it doesn't have the whole thing merged with the game either. Isn't that great.)