I know it's not a common opinion, but I hated all the "game on the side" type games they started introducing into Final Fantasy games... you know, Triple triad, Blitzball, all that crap.
I just always fucking lost at Triple Triad. Loved Blitzball though. Without realizing it I had basically recruited the best potential goalie in the game (an Al Bhed you just kind of run into somewhere). Got to the point where I went two seasons without the opposing team scoring a point.
Worst part of a game I really like? Front Mission 4 has a couple logical disconnects that you don't notice the first few times you play them, but get more annoying once you realize them. And they all have to do with access to equipment/money.
See, the B-plot of FM4 is that Darrel, Renges, and Schaffer find a crashed cargo jet filled with literally tons of gold bars. The value stated was $25,000,000 but that was before the price of gold jumped in the early 2000's. The quantity of gold is such that they need heavy military cargo trucks in order to transport it, and it was stated to be stolen from Venezuala's national treasury, so I'd say it's probably more like $250,000,000 in gold - $25,000,000 in gold would only be around 1300 lbs, which a Ford F-150 could haul. That's not my issue. My issue is that you can never use any of that money that you're carrying with you the entire game, to buy equipment. Now, yes, if you're buying from government stores that would be a problem - but 90% of the time, you're buying through the black market. No one is going to fucking care where the money came from. But no, you're stuck with the credit reward earned in battle.
Secondly, the group in the A-Plot of the game is "The Durandal", an NGO dedicated to research and development of combat wanzer technology and tactics. One of the very first scenes involves the disorientation suffered by a new pilot due to the increased responsiveness of the Durandal wanzers. Given all that, it is fairly safe to assume that Durandal's equipment is higher grade than most issued wanzers - the main protagonist is newly arrived from the French armed forces, while other members are from Russia (Zaftra, for some reason in this), Germany, Italy, and the UK. Yet, in game, your team's gear is often on par, or somewhat slower, than the opposition, unless you unlock special gear in the simulators.
Which brings me to the third annoyance in the game: Unlockables that are nigh impossible, that you are never told about in-game, that are extremely unlikely to be figured out, ever. For example, "Defeat all enemy forces before the fourth round" - on a map where all the enemy groups are distant and widely spaced, and reaching any one of them will take at least 2 rounds. If you don't one-shot each and every enemy, you cannot possibly meet this criteria. You will not have the gear to one-shot any enemy. "Save more than 4 of your suicidal allies" - they are in immediate range of the enemy, slower than the enemy, dealing maybe 3/4 of the damage your weakest party member does, with armor maybe 1/2 as effective. Your troops won't be in range at maximum move for at least 2 rounds. There are 6 of your suicidal allies, and a dozen enemies.