Need for Speed Underground on Xbox 360? Not Backward Compatible.

NFS Underground (2003) & Underground 2 (2004) are original Xbox games. Xbox 360 does not support them via backward compatibility.

Why

• BC program ended 2007. Only ~460 titles supported. NFSU not on list.
• Different kernel / GPU (NV2A vs Xenos). Emulation not implemented.

NFS Games That *Are* BC on Xbox 360

• Need for Speed: Most Wanted (2005)
• Need for Speed: Carbon (2006)
• Need for Speed: ProStreet (2007)
• Need for Speed: Undercover (2008)
• Need for Speed: Shift (2009)
• Need for Speed: Hot Pursuit (2010)
• Need for Speed: The Run (2011)
• Need for Speed: Most Wanted (2012)
• Need for Speed: Rivals (2013)

How to Play Underground Today

1. Original Xbox (disc) — Best authenticity.
2. PC (GOG/Steam) — $10, widescreen fix, mods, controller support.
3. Xbox Series X|S — Still not BC. Same list as 360.
4. Xbox Cloud Gaming — Not in library.

Buy NFS Most Wanted (2005) on 360 — it's the spiritual successor, BC, and better.