Demo - Video:

https://www.youtube.com/watch?v=PNaHIXUVKXE

Description

This mod allows you to walk freely in any room you like. It removes the collision-detection of the player (however you can be hit)
Things you might be interested in:

+ walk over any obstical you like (but you can get damage)
+ walk outside of any room-borders (for nice screenshots or so)
+ use a door from the other side (good for cursed room doors to avoid damage)

- you cant walk throught an closed door (any kind of)
- walking over spikes still causes damage
- enemys still can hit you

Afterbirth Version by 'Logical'

https://moddingofisaac.com/mod/1961/no-clip-mod-afterbirth