Instructions are built into the game. This is a retro platformer in the 'Metroidvania' style, where initially you are only able to move, not even jump! You gradually gain more abilities, from jumping to lasers to rocket dashes and missiles, until you can explore the entire space station and at last, obtain the kitty that Robot has so long desired!
It's a short game, designed for players to speed-run (it tracks your time to completion and has features to penalize/award time based on dying and killing enemies). It can take about 5 minutes for an absolute expert, about 15 minutes for a regular player, 30 or so for a first timer. My personal record is around 8:40.