God Of War 2 has 2 discs, But I only got 1

[csvo2000]

Today I bought God of War 2 for the PS2.  It only came with 1 disc no cover or manual.  My question is... Do I need disc 2?  They only included Disc 1.. Do I need Disc 2 to continue the game or was Disc 2 a Demo?  Thanks in advance for your help.

[Symptoms0fMercy]

The second disc is full of extras and stuff from the games development. Its not needed in any way to play through the game. Was this a gamestop hackjob by any chance? 

[csvo2000]

No I bought it at Blockbuster.  I purchased 5 games all the same way.

1. God of War II
2. Grand Theft Auto: Vice City Stories
3. Meet the Robinsons
4. Onimusha 3: Demon Siege
5. Siren

$2.99 each in a nice new clear DVD case, no manuals or art work.  The discs were all scratch free. 
They all may have been resurfaced.  But if they were they did a great job.  No swirl marks or
funny patterns on the discs.