Blow open tower door was a mission in Jak 3. Ashelin Praxis needed to have Cyber Errol taken out, but to do so they first would have to punch through the door blocking the way to the Metal Head tower in the Metal Head city section. Torn would drive a cargo transport filled with explosives, while Sig and Jinx were in the HellCat fighter behind him as escorts. Jak's mission was to use the turret on the cruiser to shoot down any enemies that attempted to strike at the two vehicles.
An on-rails shooter mission through the entirety of Haven City, starting from the north end of New Haven and going through the Slums, Industrial Section, the Port, and ending at the north end of the Metal Head city section. You will be attacked by numerous grunts, wasps, roboguards, sentinels, and blast bots, as well as a bunch of missiles from a missile launcher. There are also explosive barrels spread throughout the city, which can be shot to kill any nearby enemies.
The grunts' main tactic is to jump from above onto Torn's or your vehicle, while the wasps and sentinels just come flying in and try to shoot either of you. The roboguards stand still and shoot at either Torn's or your vehicle. The blast bots, on the other hand, often enough won't get a hit on either of you and are still big enough to make an easy target. Lastly, the missiles will appear out of nowhere at specific intervals, but you should have enough time to shoot them down. For this reason, the grunts and the missiles are the main danger here, although the roboguards are also a bit tricky to deal with as well, as they can often shoot either you or Torn before you manage to get a good hit on them.
This mission entirely comes down on reflexes and reaction time. As long as you can move the reticle around fast enough to kill the enemies as they gun or attack you or Torn, you should be doing okay. It remains a difficult mission ultimately, although there is a checkpoint between the Industrial Section and the Port. When you destroy the tower door, it immediately moves on onto the next mission, "Destroy Metal Head tower".