It's an HALF-LIFE 1 mod, made with HL1 engine. I was hooked on the older versions 12 years ago, it's one of the best, if not the best free mod I've ever played, and best DBZ game ever made.
They were supposed to port it on the Source Engine and I thought the project died 10 years ago, but I discovered yesterday it was still alive and under development after 17 years and they're working on a final version, still on HL1 engine and it looks godly. That's what that video shows, it's still a work in progress though.
They're holding that final version until it's completely done and haven't released any new playable version since 2008 (except an open beta of the final version playable on hamachi or LAN), so the current playable version is 1.2.3 and looks like this :
It looks like regular HL1 mod but the gameplay is dope with a crazy learning curve. There just a few servers left on that version, most people are waiting for the final one to be released to come back to the game, but it's still fun ;o