1. Bunny Hopping - It works very much like the QuakeWorld bunny hopping. You just need to use the slide mechanic + QW bunny hopping.
2. Hand Grenades - One mechanic that was really great about Quake 2, but was left out of Quake 3, was hand grenades.... Titanfall 2 has them working in all their glory.
3. Double Jumps - Very much in the vain of Unreal Tournament.
4. Rocket Launchers - It actually has rocket and grenade launchers + Star Wars sound effects.
5. Duel - There is a duel mode very similar to that found in CPMA duel arena. Two players with basically a rocket launcher, rail gun and hand grenades match up in a circular arena.
6. Grapple Hook - I remember playing (on Heat.net) Rocket Arena 2 with just Railgun, Hand Grenades and Grapple Hook... it was a blast.
7. Titans - well and there's titans...

P.S. I don't care if you play it or not. Just appreciating the old school aspects of the game.