"It's like Robotech plus Gundam, only not."
Barely anyone I've spoken to has even heard of this system, which is a shame. People may be more familiar with Talsorian Games' other flagship product, Cyberpunk 2020, but in my opinion it's Mekton, the game of supposed strategy and giant robots, that wins.
Mechanics-wise, it's a simple system at heart but one which is overcomplicated by nebulous attempts at "realism" married to a setting which wants you to kick reason to the curb and fight the power. There are 10 stats, many of which would be Skills in D&D - Attractiveness (Charisma, or how moe/gar you are), Body (Constitution), Cool (Wisdom and your Fort/Will saves in one), Empathy (only used for skills), Move (yes you can be faster than Usain Bolt painted red), Intelligence and Education (two stats which combined govern your skill allowance), Luck (a pool of bonuses), Tech (used for skills) and Reflex (if there is going to be combat, you need a 10 in this.)
Stats go from 0-10, with big numbers being good. You then get a number of Skill Points equal to your INT and EDU plus 10. Skills are used in checks, like D&D, and also in combat (there are distinct skills for shootan, movan and robot fightan.) They also go from 0 to 10, but some can't be initially bought at a higher level than 5.
Character creation is pretty simple, though. The game recommends a 70-point buy which may as well be a 40-point buy after you've got the requisite 10s in INT, EDU and REF. For NPCs they use a 40-point buy, although dice rolls for stats are suggested as alternatives (roll 10d10, re-rolling until you've got more than 40 points to allocate, or roll 1d10 for each stat re-rolling 2s or less). Then comes the fun part. Lifepaths. The vocal fan base of Maid RPG knows what this is all about, but to explain you essentially roll a ton of d10s, and they do your backstory for you. You can end up with one-eyed lesbian sex fiends, angry engineers with negative Attractiveness who look like the Phantom of the Opera meets the Elephant Man, trench coat wearing anti-heroes and tsundere bridge bunnies.
What happens next is you CHOOSE YOUR DESTINY. You can either be a rookie, which means you get less skills (only your starting pool of skill points) but bonus EXP, or a pro, which means you can say your character is old, and spent years honing his skills in certain careers like MechWarrior (oddly enough Microsoft Word capitalised that for me), nurse, cop and computer programmer. There are loads of careers, and each one you pick gives you a bonus point in 5 skills, which can bring capped skills over level 5. The problem is, doing this locks you out of bonus EXP and also means you take longer to level up. But you're awesome and probably playing Roy Fokker, so it's worth it.
Character creation is littered with anime name drops, as befits a book about what are essentially weeaboo fightan robots, and the generic 80's style may grate. But if you give up now you miss the fun part.
Robot design is either simple or massively complex. There's a whole splat book, Mekton Zeta +, which allows you to design every little aspect of your dream machine, and is great fun once you've got your head round it. Or you can use the core rules, which use preset weapons and parts and basically turn it into MechWarrior 4.
I'll talk about Zeta +, because it's more interesting. Mech creation is really hard the first few times, because there are so many words and things. But, in brief, here's how it works:
It's not that simple, but a worked example would be Xbox-huge. Suffice to say, if you've seen it in an anime or show, it's probably buildable. There are rules for scaling things up or down, so you can do anything from a Space Mariner with his massive Fight Power up to the SDF-1. The problems come in when you realise exactly how badly proof-read and laid out the rules are. Sections conflict with each other, and are needlessly complex. Don't even get started on the rules for fueling aircraft.
Then you have the problem that afflicts D&D 3.5, Battletech and most anything else that's customisable. Powergaming. You need to be an eagle-eyed DM to stop people building totally invisible robots with weapons that can destroy anything in one shot. Even flavourful items like the Magnetic Resonance Lens are abusable. It's a cheap-ish upgrade which allows you to "see through solid objects, marking out living targets as dots." It's meant to be used, I presume, for finding out where a hostage is or something. However, it can be used to call shots against a target's reactor, or to allow artillery to fire as if it were direct-fire.
So, you've created your fightan robot and your badass ORIGINAL CHARACTER DO NOT STEAL. It's time to TEST YOUR MIGHT. Slam on some Fire Bomber or something, it's time to roll.
Then get your Battletech minis and hex grid. Mekton uses minis, because there are a lot of rules about facing. Or, you can ignore all that and use Maptool. Anyway, the meat of combat is as follows.
You start by rollan initiative. You'll do this at the start of every turn. All mechs have a Reflex Stat of their own, which is sort of a "how heavy is this mech" rating. It's a negative modifier to your own REF (see why it has to be 10? Any less and good luck keeping anything larger than a Flea upright) and since every action is a REF plus relative skill check, you need it as high as possible.
Initiative is d10+Mech REF, (your REF minus the mech's modifier). Then you fight. You have two standard actions a turn, so you can MOVE AND SHOOT if you like. Doing anything that's not moving is an opposed skill check of D10+Mech REF+Relevant Skill with your opponent, or a check against a DC. When you've fired your laser at someone, it's time to deal damage.
Start by rolling to Hit. Then take the difference of your score and your opponent's after modifiers (Say I roll D10+17 and he rolls D10+3, the result being 27 vs. 4. The amount I "Hit by" is 23) and see how huge it is. Rapid-fire weapons hit once for each point you "hit by" up to their max burst. For every 5 points you hit by, one hit is upgraded to a Critical Hit. For every 9 points you hit by, one Critical hit is upgraded to a Mega-Critical hit.
Then roll location. This is easy. Critical Hits can choose to roll on the "Special" or "Cinematic" location tables, normal hits have to hope for a natural 10 to get on them. Mega-critical hits roll location as normal, but ignore armour.
Then do damage. Subtract the target armour from your damage, after Armour modifiers like AP ammo. The target takes that many Kills of damage (basically Battletech's Internal Structure,) and loses 1 point of Armour for each individual hit. This leads to an epic exploit where six 1-damage guns will be more destructive against a heavy mech than 1 6-damage gun, because you're shaving off 6 points of armour every turn. Still, it's no worse than MG spam in CBT.
That's pretty much it, actually. Melee is like shooting but done with its own tables to depict special attacks, and between-battle RPing is much like anything else.
To conclude, therefore:
FINAL VERDICT: 6/10, but a 9/10 if you like robots and huge amounts of crunch in your gaming. 10/10 if you like giant robot anime.
So an 8.3/10 average.