Coreball online is a browser timing puzzle about launching small balls into a rotating core without causing collisions. Each shot adds a new obstacle to the circle, so the available gaps get tighter as the round continues.
The challenge is easy to understand and hard to rush. A safe launch depends on the current spin angle, the position of existing pins, and the time it takes for the next ball to reach the core. Strong runs come from waiting for a clear opening instead of firing as soon as a gap appears.
This page loads Coreball online through a local wrapper around a validated browser source. The validation pass returned HTTP 200 for the wrapper and inner playable page, found no X-Frame-Options header, found no frame-ancestors CSP directive, and did not detect blocked upstream domains in the checked HTML.