I've been into the BattleTech universe since I was a kid (when I first got MechWarrior 2 on Win95), and nothing has frustrated me quite as hard as some BattleTech missions.
There are some mega mod packs for that game too that drastically change the ruleset (hit mechanics, how cover and evasion works, etc) as well as add in hundreds of new units ('Mechs, armor, VTOLs, even Clan Elemental infantry if you're playing one of the post-3050 mods). RogueTech is absolutely fucking infuriating, but so far it's the closest you can get to tabletop rules.