If the game freezes, just click inside it (games can get unresponsive if you click elsewhere on the page).
Collect the key to unlock next chamber's entrance.
Collect all gems to get a live or a purple gem.
Avoid bats, scorpions, pitfalls and other nasty things.
Read the scrolls in the game mindfully.
Arrow keys to move.
Space bar to jump or swim.
Y to sprint.