LetsERush is a Windows desktop game designed to make mental arithmetic quick, focused, and engaging. Its clean, distraction-free interface turns calculation practice into a 60-second sprint: players solve as many problems as possible, build a streak, and try to beat their personal best. Questions begin with single-digit addition and subtraction, then progress to multiplication and division as scores rise, adapting the challenge to each run.

Gameplay rewards both speed and consistency. Answers submit as soon as the required digits are entered, with a bonus for responding in under two seconds. Five consecutive correct answers increase the score multiplier, up to 5×, while a mistake costs three seconds and resets the multiplier. Available as a free Windows download, version 1.0.0 supports Windows 10 or newer on 64-bit systems. The approximately 5 MB installer requires no administrator rights, and the game runs offline after installation. LetsERush states that it collects no telemetry while players are playing. The app can be uninstalled through Windows Settings, with installed files removed cleanly.