Today, Dragon Ball Z: Budokai Tenkaichi Tag Team is a cult classic. If you have a PSP, PS Vita (via PSN), or a capable emulator on PC/Android, it is absolutely worth hunting down. It's not the most polished or balanced DBZ fighter, but it is arguably the most on a portable system.
Dragon Ball Z: Budokai Tenkaichi Tag Team is a fascinating artifact. It represents a “lost” evolution of the Tenkaichi formula. While the main console series died after Tenkaichi 3 (until the recent Sparking! Zero ), Tag Team showed a path forward—team-based combat.
Key transformations (Super Saiyan 1-3, Fusion, etc.) are present, and each character retains a unique moveset of Blast 1 (buffs), Blast 2 (powerful Super Attacks), and Ultimate Blasts.
Given the PSP's hardware limits, Tag Team doesn't match the 150+ characters of Tenkaichi 3 . However, it boasts an impressive roster of over 70 characters, covering the entire Dragon Ball Z storyline (Saiyan Saga to Buu Saga) plus a handful of movie characters (Broly, Cooler, Janemba, etc.) and even several from Dragon Ball GT (Super Saiyan 4 Goku/Vegeta/Gogeta, Omega Shenron).