Left/Right or A/D - Move.
Down or S - Crouch.
Up or W - Small Jump.
Space - Big Jump (holding it down will increase height).
Get to the top floor. Collect golden wrenches and hard hats (for health). Avoid flying rivets, chihuahuas, traps, and angry aliens.
If the game freezes, just click inside it (games can get unresponsive if you click elsewhere on the page).