Dragon Ball Z Budokai HD Collection

This is a basic run-down of Teen Gohan's Dragon Universe

(To unlock Teen Gohan you will need to defeat Frieza as Kid Gohan in Kid Gohan's Dragon Universe)

Earth (Cell Saga)

1) Mountains (C1R1) - Cutscene with King Kai. You will gain a random capsule
2) West City - Cutscene
3) Goku's House - Cutscene with Goku and Chichi
4) Make your way towards Kame House for an automatic cutscene with Master Roshi
5) Desert (C3R3) - Cutscene with Piccolo
6) West City - Cutscene with Bulma. You will gain a random capsule
7) Central City - Cutscene. You will unlock the Urban Area Stage
8) Red Marker - Here you will fight Piccolo
9) Red Marker - Here you will fight Krillin
10) Kami's Lookout - You will gain the Super Saiyan capsule. Here you will fight Goku
11) Goku's House - Cutscene with Goku
12) Cell Game Ring - Here you will fight Cell in his Perfect Form
13) Plains (C3R2) - Cutscenes
14) Red Marker - You will gain the Super Saiyan 2 capsule. Cutscenes. You will gain the Super Kamehameha. Now it is time for Teen Gohan's boss fight! Cell in his Super Perfect Form!!!! And thus you will unlock Gohan and the achievement!