Drift, shoot, and survive. I originally played this on an Acorn computer at school in the year 2000. My god I'm old. Desktop only — you need a keyboard.
Classic vector-style Asteroids: every edge wraps, the ship has inertia, and there's no reverse — pushing down just slows you down. Each level spawns one more rock and bumps asteroid speeds by 5%. Hit a large rock and it splits into two medium, then small, then tiny; tiny rocks pop on the next hit.
Score = points per asteroid (tiny rocks worth the most) multiplied by a speed bonus. Beat all 10 levels for the win screen. Your best score is saved in this browser, but gone forever when you leave.