(Vague spoiler warning)
One of the moments that always struck me while moving through Mad Max was a moment towards the end of the game's storyline, after you've obtained the V8 engine that Max sought so doggedly. After a rescue attempt goes awry Chum strands Max in enemy territory and flees back to the ruins of their former hideout leaving Max without access to the car you've spent the whole game building together. Once you make it back to friendly ground you're forced to give chase and recover Chum and the car alone as Max brushes off the other character's attempts at convincing him to give up his endless struggle and reconstruct his life with them.
Up until this point, Chumbucket has been more than just a random NPC. He's the only one capable of repairing the car when it takes damage without cutting into your wallet, he acts as a lookout and gunner to help you fend off bandits and assault convoys, and he acts as a guide to the different regions of the world, pointing out areas of interest, supplies, etc. Truthfully, he's Max's only friend in this hostile environment and during the first of these "drive time" missions the only dialogue you experience is Max incensed fuming about his weakness for trusting Chumbucket. It's a welcome change of pace from the rest of the game and does a great job of reminding you of just how vulnerable Max is without Chum as the car you're forced into using for this bit has no weapons of any kind outside of Max's shotgun, it has basically no armor, and repairing it costs a significant amount of scrap (the game's currency, like bottlecaps in Fallout). At the height of your power, just after receiving a powerful V8 engine and after having significantly elevated Max and your car, referred to as the Magnum Opus, beyond the capabilities of what you started with, I think it's a great moment for it all to taken away like this.
After you find Chum, you're treated to a somewhat aggravating boss fight and a color-draining reveal: while you've been busy fighting, the main villain of this story (the warlord "Scabrous Scrotus") was acting on the info gleaned from torturing Chum about an escaped concubine named Hope and her daughter Glory, whom Max had grudgingly befriended. As you frantically race the Opus to the opposite end of the map to hopefully beat the clock and stop their impending murder, Chum is the one having the one-way conversation as he pleads for Max's forgiveness. It's a far cry from how the game started as a relatively low-stakes psedo buddy comedy about two guys building a car together in the Australian desert, and losing major characters like this in way that you have no agency to change resonated strongly with me, I think because throughout this game I was wishing that the developers had implemented some more "painful loss" mechanics into the actual gameplay, like having enemies threaten to steal your car or capture Chum for their own faction - both of which they seem to just ignore.
Obviously this is a subjective thing, but I've always been kind of struck by these two sections of this game in particular as being more memorable than the rest just because they took a chance on making the player feel bored or temporarily powerless and it's just such a refreshing change of pace.
