12 Things You Didn't Know About Half-Life 2

When PopCap Games first released their puzzle game Peggle back in 2007, it received positive critical reception and proved highly addictive, combining elements of pinball and pachinko. Seeing an expansion and two follow up titles, one entry that often gets forgotten is Peggle Extreme.

It might seem odd to list this here, but Peggle Extreme uniquely featured levels inspired by Half-Life 2, along with Portal and Team Fortress 2. Featuring 10 levels and five challenges, it initially came packaged with the PC version of The Orange Box but was later released as a free download in 2008.

Learning that Valve staff often played Peggle in their offices, PopCap games proposed a crossover that paid tribute to Valve’s Orange Box titles, one that Valve happily accepted.