Big Doom is a mutator that resizes Doom maps, making them either very cramped or just huge.
And, yes, this can definitely break maps and make them unplayable, so use this at your own discretion!
Big Doom v1.3.0 on Google Drive
• Added new feature "Randomness", which randomizes the scaling for each map. This feature respects the option to scale X, Y, and Z axes seperately.
• Added new feature "Use Proportional Clamping", which maintains the shape of the map when it must be clamped to keep from exceeding engine limits, i.e. no more super-tall ceilings due to disproportionate clamping.
• Added new feature "Preserve Floor Heights", which scales the Z-axis by moving the ceiling only. It does not guarantee that the map will not break, but it does make the map more likely to be traversable.
• Clamped scaling factors to respect maximum map sizes in (GZ)Doom.
• Fixed wall textures still scaling on X axis even if side texture scaling was disabled.
• Added option to scale maps differently for X, Y, and Z axes.
• Initial(-ish) release!
• Using "Preserve Floor Heights" may expose untextured sides, creating HOM artifacts, since it scales sectors irrespective of their neighbors. I am considering a fix for this.
• Some texture scaling options may cause middle textures to look wrong. I am considering possible fixes for this.