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Aren't there Gundam games too?
Yeah and EXVS is a Gundam game. On the ps4 there are a bunch. It is a rabbit hole of stuff but I can throw out some titles in their respective categories. Since western/eastern mech titles have differences. Most of the games are going to be action titles. FYI I prefer Japense mecha style over Western so my thoughts are more biased in that sense. Mech warrior games are neat but never hold my attention. Phantom Brigade is super cool but lacks story content and is more for the hardcore mecha/srpg kind of fans(but only on pc for now).
Japanese
SRPG:
Super Robot Wars: There are a ton of these and even the most recent can be purchased in english without having to import.
SD Gundam G Generation Cross Rays: one of the first of these to be brought to the west outside of SRW. I have like 120 hours and still havent finished this game. Be warned that this is very niche.
13 Sentinels: OK so this game... is fantastic. However, it is a cross between interactive story and SRPG. The SRPG sections are not appealing to look at but feel fantastic once the game introduces enough of the mechanics. However, it does feel very niche and sadly... a little weeb. Nonetheless, amazing game.
Action:
Front Mission Evolved: not quite the same as the beloved previous titles but it is like Armored Core in a sense.
Armored Core Titles: For Answer is probably the best one to pick up here.
Gundam Battle Operation Online 2: This is a f2p PS4/PS5 PVP game that typically pits 2 teams against each other. It is fun and frustrating. Probably takes about 5-10 hours to get proficient at the aiming but countless hours to get what you really want. I love this game and wish they had it on PC.
Zone of the Enders Collection: Classic PS2 games that are worth buying for all eternity for any japanese mecha fan.
Dynasty Warriors Gundam: Self explanatory
Lost Planet Games: This is kinda a mix since there is some really cool mecha action but it is mostly a third person shooter.
Project Nimbus: This game is OK. It more scratches the itch for a more hardcore kind of fan. It is repetitive and lacks in the quality department but it is fun if you can go beyond that.
Fighting:
Gundam Extreme Versus Titles: Maxi Boost On is the most recent one and a game that I have sunk like 70-100 hours into. Very challenging but the community is super supportive and great.
Virtual On: I imagine there was one somewhere on the ps3/ps4 since they were so beloved as fighting games
Western:
Fighting:
Override Mech City Brawl: There are 2 games of this. I have only played the first and it was fun. However, don't expect to play online much since the game is designed for MP but the community seems to die quickly after launch or small bumps from sales.
RTS:
Iron Harvest: I only added this game to add to the list but I really didn't like this title. Nothing about it was particularly good to me. It was kind of a company of heroes with "old fashioned" mechs mixed in with horrible voice acting and poor quality.
Shooter:
Titanfall 1& 2: 1 is more MP based(which I put far more time into since it felt better for MP loop). While 2 has a fantastic story. It is more shooter that revolves around Mechs but still a great game.
Hawken: Not sure if this is around still(doubt it) but I dumped like 40 hours into it and it was nice visceral combat. MP only though and I haven't heard a peep about it for a long time.
Action:
Strike Vector Ex: This is peak action gameplay. This is probably the biggest hidden gem in this list.
MOBA:
Airmech: it is a decent little moba. Not sure it is still alive but it was neat when I played it. Didn't keep my attention for long.
Side:
Hardcore Mecha: LOVE this game. It is a side scrolling game from a Chinese developer that loves Japanese style mechs. This is also very niche since it is based on SD models but this game is the essence of mech games.