Speaking of achievements, there was a game for the Nintendo Gameboy, starring Bugs Bunny. A miserable game all around, but I still remember the pitiful "reward" at the end of the final stage:Well done! Of the thousand plus games I own, over twenty years of playing them, I think I only ever 100% achieved less than ten of them.
Nothing changes, no special screen or graphic, just the same end of the level, and the phrase in poor English: "Congratulations, you are good player".