The track listing for Phineas and Ferb: Across the 1st and 2nd Dimensions' is as follows:
1. 'Everything's Better With Perry'
2. 'Perfect Day'
3. 'Hey Ferb'
4. 'Brand New Best Friend'
5. 'You're Going Down'
6. 'What 'Cha Doin?'
7. 'Summer (Where Do We Begin?)'
8. 'Perry the Platypus (Extended Version)'
9. 'Takin' Care of Things'
10. 'Not Knowing Where You're Going'
11. 'Brand New Reality'
12. 'There's a Platypus Controlling Me'
13. 'Mysterious Force'
14. 'My Ride From Outer Space'
15. 'Come Home Perry'
16. 'Back In Gimmelshtump'
17. 'When You Levitate'
18. 'You're Not Ferb'
19. 'Robot Riot'
20. 'Rollercoaster'
21. 'Carpe Diem'
22. 'Kick It Up a Notch' feat. Slash
Only one extended song? That's a shame...
I checked Hey Ferb to see if it was longer on the CD or not, and it is by about a minute. So I'm going to check all the songs.
1. 'Everything's Better With Perry' TV = 1:45. CD = 2:51
2. 'Perfect Day' TV = 1:11. CD = 1:59
3. 'Hey Ferb' TV = 1:17. CD = 2:20.
4. 'Brand New Best Friend' TV = 1:01. CD = 3:43.
5. 'You're Going Down' TV = 0:59. CD = 1:59.
6. 'What 'Cha Doin?' TV = 1:15. CD = 2:06.
7. 'Summer (Where Do We Begin?)' TV = 2:34. CD = 4:24
8. 'Perry the Platypus (Extended Version)' TV = 0:47. CD = 4:40.
I think we've gathered that all the songs are pretty much longer on the CD. Whether it's additional lyrics, or just music, we'll find out... But I can't wait for the extended Perry the Platypus theme!