ballpark is built for precision clicking with a mouse or trackpad. you can play on touch, but finger taps aren't accurate enough to really compete.
a number appears above a line. click the spot on the line where you think
that number lands. closer is better — your score is how far off you
were, as a % of the range. chase perfect, keep a streak going.
easy / normal / hard change the range and how strict the grading is.
daily — 5 fixed rounds, the same set each day. share it,
build a day streak.
invert — classic, but the scale is flipped: max on the left, 0 on the right.
world — place a real-world fact (moon distance, Everest height...).
reverse — the marker is shown; you type the number.
survival — one miss ends the run. how long can you last?