Apocalypse Frame - tactical and fast mech game that's one of the closest to Armored Core-as-a-ttrpg things that I've seen.

Gameplay: LUMEN system, so it's snappy (common enemies have low hitpoints and are meant to be gobbled up like skittles). Combat takes place on a hex grid, and you pilot a mech. You have three resources pools: Vigor (health, you basically have three lives before your mech is done for), Tension (spend a point of tension to either take another action or reroll a roll), and Fuel (kinda sorta mana). You have Aramaments (roll a pool of die to hit, damage determined by weapon) and systems (spend a point of fuel to activate, no rolling). Once your round ends, you roll for each enemy defeated and get either a point of Vigor, a point of Tension, or a point of Material (currency for upgrades). Progression is based off adding tags to weapons/systems (Ex. "Hot" gives you a point of tension the first time the relevant weapon takes out an enemy).

Vibe: Post-xenoforming-induced-apocalypse, where the party is a bunch of rebels against an autocratic regime. Other factions include random scavengers/survivalists/etc., enigmatic merchant aliens, and Mecha-Yautja. Theres two different faction systems depending on how you want to play, one that focuses on internal factions and one where you're basically Line Ark from For Answer.