I had my idea of a TFTD intro, which borrowed elements from the UFO Defense intro. Aliens attack a ship and kill civilians. At an XCOM base a sonar picks up a contact and goes "Warning! Warning! USO detected!". XCOM Aquanauts get ready for battle, wearing their basic diving suits and arming themselves with gauss weaponry and a vibro-blade (UFO Defense has soldiers wearing improved armor and basic weaponry, my TFTD intro will have soldiers wearing basic armor and improved weaponry).
They put on their helmets and enter a Triton with a Gauss Colecanth. The triton submerges then heads toward the attacked ship, then surfaces and flies to the ship and lands on the deck. The aquanauts then take off their helmets as the Colecanth Emerges first, firing its gauss cannon at the aliens. A male aquanaut then fires his gauss rifle rapidly (in a similar fashion of an XCOM UFO Defense soldier firing his rifle). As a female aquanaut is being fired at, she takes out her vibro-blade and runs to the alien firing at her, dodging sonic shots. She then pierces the blade through that alien, with blood coming out of it. As the blade is pulled back, the alien collapses on the ground. The Colecanth continues to shoot at aliens and the male aquanaut continues to fire his gauss rifle. The aliens then proceed to jump overboard and swim underwater away. The scene goes underwater, where a dreaded tentaculat watches the aliens flee from the ship. The scene then goes into the title.
My idea of an intro gives a more upbeat and more revealing intro, showing the SWS, melee combat, and a dreaded enemy. This intro should still use cartoons, like in XCOM UFO Defense intro.
