Energy
A level that crashes and restarts takes a second heart from the player
A phone call, a crash or a double tap, and the same level start is charged twice. Here is the small record that charges once per real attempt, lets a broken one carry on, and refuses to bill a finished attempt again.
The refill clock shows 0:00 for a second before the heart actually arrives
A countdown that rounds down tells the player "now" while the game still says "not yet". Wrong labels, jumps from 59:59 to something odd and updates that drift are small things that make people distrust the timer. Here is how the label should be built.
A forgotten crop should shrink gently, not be harvested at full size a week later
In farm games with real-time growing, an ignored field either stays perfect forever or dies, and both feel wrong. Here is a ripeness curve with a fair window, a gentle loss and a floor, so that coming back late costs a bit but never everything.
A daily activity bar with five chests loses the ones the player never tapped
Daily goals fill a bar and open chests at set points. Players skip stages, overshoot the top and leave at midnight with chests unopened. Here is the bookkeeping that keeps every stage claimable once and pays out what was earned but forgotten.
Leftover event energy vanishes when the event ends, and players feel robbed
A time-limited event with its own energy leaves players holding some at the end. Throwing it away stings; keeping it forever breaks the next event. Here is a conversion to a smaller reward that works even if the player returns weeks later.
Replaying the same level for rewards should tire out the rewards, not the player
Without a brake, the best level to replay becomes the only level anyone plays. A tiredness meter that lowers the payout, recovers on its own and never turns the reward to nothing keeps replay fair. Here is how to count it.
A power gauge that fills from matches should not refill itself during the bonus
Match games often have a gauge that fills with good play, fades when you stop, and triggers a short bonus when full. The bonus must not restart itself, and the fade must not begin the moment you pause. Here are the stages and timings.
Lives sent by friends are lost when the player's hearts are already full
A friend sends a life at the wrong moment and it vanishes, or a pile of old gifts floods the bar all at once. Here is how an inbox keeps gifts until there is room, drops the stale ones and ignores repeat senders.
Players send the same friend ten life gifts a day, or none because the limit never resets
Sending lives to friends needs two kinds of limit that people mix up. Here is a small bookkeeping rule for both, how it resets at midnight without a timer, and why a failed send must not use up the allowance.
Hints should cost something, but not erase the star rating of a nearly perfect run
Hint tokens are an energy of their own: one free per level, then paid from a bank. Good design lets a hint or two pass without punishment while many hints clearly cost stars, and never gives a finished level zero stars.
A phone call or a swipe away should not burn the clock of a timed level
Timed puzzles go wrong on phones: someone calls, the app sleeps, and the player returns to a lost level, or the app is killed and the clock is lost altogether. Here is a stopwatch that counts only real play and survives a crash.
"Enough energy for 5 more levels" is a lie for a player who loses half the time
Dividing energy by the cost of a level assumes every try is a win. Players feel cheated when the hint is wrong, and the maths breaks for newcomers with no history. Here is an honest estimate that behaves with few or many tries.