There are loads of adversaries to fight in Batman: Arkham Origins, including at least 8 different supervillains such as Electrocutioner and Copperhead (labeled "assassins" in this game). You need to gain power in order to beat them, and your primary method of doing that will be buying new batsuits. Luckily, there's an entire wardrobe worth in here, spanning the entire Batman archive all the way from the 1960s to Injustice: Gods Among Us (the most recent brand new one, aside from this game). Read on to find out how to unlock every single one of the batsuits!
You start off with the new Arkham Origins batsuit, and right from the beginning you can buy any one of the Tier 1 batsuits that you have the upgrade points for. The Long Halloween batsuit is the only one that's available to purchase initially. If you log into the WBID unlockables, you will be able to unlock a second one, the Red Son batsuit. The power level is about the same, but this suit has bonuses, such as defense from attacks while stunned, and from electical attacks.
To get the tier 2 batsuits, you have to get to the end of the missions in Uptown Gotham, and then you have to beat the boss, Deadshot. Once you do this, you can buy one of three new batsuits. The Arkham Origins Mk. II batsuit is the cheapest one, but is the least powerful, while Earth Two is more expensive, but more powerful. You can also get the Liberty Files batsuit (World War II era), but you can only get this by spending Waynetech points, not upgrade points. This one, however, will double the damage that you can do with basic attacks.
To unlock the tier 3 batsuits, first, you have to beat Copperhead in the Docks area. Once you do that, you can buy one of three new batsuits. Arkham Origins Mk. III is the cheapest and is weakest in power out of the tier 3 suits, and has no bonuses. Thrillkiller reduces bleed damage and critical damage and is more powerful, but slows Batman down. This one is midpriced. The New 52 suit has medium power but drastically increases Batman’s speed, and adds bonus protection from basic attacks and fire attacks.