The Saboteur

• If you're having trouble with some missions, try blowing up Nazi targets of opportunity in the area, especially towers, they don't respawn so it means fewer things to see or shoot at you.

• The two perks you should buy are the silver and gold "Mechanics" perks. Some of the vehicles you have to collect for these are very difficult to find, and then a pain to get back to your garage

• The most useful perks to try for early on are "Brawling" II and "Evasion" I and II. Others will come naturally over time or can be saved for later.

• Specifically, I grinded for some of the perks that unlock weapons early on, and I think it was a bad choice because I skipped over some of the intermediate weapons that you unlock via story mission progress.

• The only missable perk is "Brawling" III, but you'd literally have to go freeplay crazy to deny yourself this perk. If you don't have it by the time you unlock Paris Area 3, then it might be time to start working on it before you kill the game's remaining generals.

• You can pass through "yellow" checkpoints (marked on your map with a yellow warning sign) any time. Just take it slow. It's easier to pass through checkpoints if you're not disguised. The one you pass through early in the game while hauling a car may be bugged, though.

• The "Demolitions" III perk is bugged. Once you earn it, you'll only have access to the Super RDX until you reload the game (whether because of mission failure or turning off the console. Not sure if you lose it if you die but don't reload).

• Propaganda speakers can be destroyed with gunfire. You don't have to waste dynamite or RDX!

• There are two cars with built-in machine guns that are not visible from the outside. You don't count as "armed" for alert purposes when driving these cars (but then the guns aren't super-effective either)

• If you sprint before jumping you can jump really far (say, from one building to another, sometimes)