Raid
he hits harder every time. he also misses wider.
rob a coconut grove while its owner loses his temper, and steal in the gap his own swing leaves
The man winds up another notch with every coconut taken: angrier means quicker, more frequent, higher throws, but also wider misses and longer recovery after each swing. The run gets louder and looser, not simply harder.
Concepts: arousal, tradeoffs, anticipation.
An interactive you play with one thumb, on Wundr.