Basic Trope: A reward that serves no other purpose than to be a proof of an achievement.
Straight: In the action RPG game, Chronicles of Troperia, Alice and her group of adventurers can defeat a number of progressively difficult Bonus Bosses, culminating in Quazarx, the Dimension Lord, which is the hardest boss on the game. For each one of those victories, they get cool statue built on the capital city... Which only serves for decoration.
Defeating the Bonus Boss on Chronicles of Troperia grants a reward that greatly alters the mechanics of the game up to that point. For example: The ability to fly when, so far, you have lacked the ability to jump!
Every achievements in the game grants a change to gameplay, even if it's trivial.
The game is completely boring but all of the achievements makes the game more awesome.
Defeating Quazarx grants Alice the title of "Great Dimensional Champion", which at first seems useless until you notice the merchants have started to offer a hefty discount on all their services and products. Besides, you also gain access to a secret area where you can get awesome (and previously rare) items and equipment.
After winning the "Champion's Tournament" mid-way through the game, you obtain a shining trophy to decorate Alice's home. However, near the end of the game you met with Armax, the Ultimate Blacksmith, which offers you to create Alice's ultimate weapon if you can get a chunck of Troperium for him to forge it. And fortunately for you, the trophy turned out to be made of it.
All those trophies appeared to just clutter up Alice's house, but they're all made of metal and you can smelt and craft them into a decent set of armour.
Double Subverted: After winning the "Champion's Tournament" mid-way through the game, you obtain a shining trophy to decorate Alice's home. However, if you interact with said Trophy, it turns to be a portal to a pocket dimension where all your starting weapons get upgraded to Immaterial Weapons, which aside of looking incredibly cool and glowing with a ghostly light... Don't do anything special, they are basically a cosmetical upgrade of your starting weapons.
Parodied: After defeating Quazarx in what's possibly the most epic battle on the entire game, the dreaded Dimension Lord himself recognizes your superior abilities by giving you what is (according to him) the most prized award in the entire universe: An autographed photograph of him with an incredibly sappy dedicatory and a nice frame.
Zig Zagged: ???
In Chronicles of Troperia, every significant Side Quest yields a substantial and helpful in-game reward, no exceptions.
Alternatively, no rewards are cosmetic.
Enforced: In the XBo- Erh, I mean:Z-Prism 720 gaming console, Achievements Milestones are actually a required feature for any released game, so the developers have to include them aside the fact that some of them might yield an actual in-game beneficial reward.
Invoked: Unfortunately for the king of Troperia, the war has greatly weakened his economical and military force, so it's impossible for him to grant Alice and her group a prize worthy of them, so the only thing he can do to honor their deeds is to try to immortalize their names in history. hence, the construction of the statues for them and their new Champion titles.
Alice: I'd love if once, at least just once, we could get an awesome reward after defeating yet another of those annoying Dimension Lords. Bruce: We are heroes Alice! We don't do what we do for the fame, fortune nor the rewards, we do it to make the world a better place. And for each Dimension Lord defeated, I'm sure we are releasing a lot of people from a life of undeserved suffering. Alice: Darn it, I think you're right! Sorry about that Bruce, I think I was being selfish. Bruce: No problem. Besides, we don't necessarily go empty handed all the times. Just look at the kickass statue of me they carved!
Conversed: "And what's your reward after defeating the most difficult boss the game? A new weapon? A secret area? A substantial power-up? No: A photograph of the game's heroine on lingerie. Seriously: What the hell?!"