The followup to Mars: War Logs (chronologically they take place concurrently and there’s a few retcons, so you don’t need to play that first) manages to improve upon almost every single aspect and adopts more of a Deus Ex feel.
The previous technical issues (keybinding, refresh rate, FOV) have been addressed, environments are much larger and varied visually, combat’s far more fluid, companion commentary has been greatly expanded, many quests now have multiple ways to resolve them, and the dialog and voice acting are both much better. So what hasn’t improved? The backtracking. There’s still a ton of it (particularly if you want to do the side quests) and there’s no fast travel system to speak of.
The combat difficulty has also been increased a bit. The name of the game now is disruption… also avoidance. You do not want to get hit under any circumstance because it will hurt. Badly. So you’re basically left with two paths to choose from: A strength build that switches between Warrior (multiple enemies) and Guardian (1-on-1) or an Agility build that specializes in Rogue. Rogue is insanely good since it has a ranged attack and you no longer take damage while dodging… but it lacks an AOE attack and has comparatively limited disrupting abilities until/unless you unlock the relevant passive handgun skills.
As far as Talents go you’ll want at least one point in Lockpicking, Crafting, & Science (whether you need a second point depends on your companion bonuses; the third can be gained by specific armor). Max Charisma if you want to resolve quests that way, and put at least two points in Stealth if you’re playing on any difficulty higher than Normal (using headgear to get the third). The one point in Exploration you can get from either headgear or a companion is plenty. Attributes are straight-forward with Warriors & Guardians focusing on Strength/Constitution (or Strength/Power) and Rogues on Agility/Power while Skill choices depend on what stances you prefer to use. Expect to reach level 34-36 before heading off to the last area.
All in all I’d say the game is definitely worth picking up on sale sometime if you’re a fan Deus Ex-y RPGs.