This is based on opinion. Please don't list it on a work's trope example list.
Tear Jerker / Nintendo Wars
Nintendo DS had one in Advance Wars: Days of Ruin, when Brenner, injured and alone, stalled the enemy long enough for his unit as well as former enemies to escape. Will and Lin were hit particularly hard for some time.
Also how we are introduced to Will in Days of Ruin. He was the only survivor from an entire military academy and had to dig himself out of the rubble. Then he spent an unknown amount of time wandering the remains looking for anyone. His look ◊ on his face really shows it
While the original advance wars trilogy only has one real moment, it's a fairly large one. It's in the Black Hole Rising mission "Toy Box", where Olaf, after furiously defeating Lash for utterly destroying the town of his birth, starts depressedly pointing to the various remains of the town's landmarks and reminiscing about his childhood. You can almost see the tears in his eyes as he does it. The Blue Moon theme playing in the background also adds to the emotional tone.