"All warfare is based on deception." -Sun Tzu

Even though a lot of people like to, don't constantly shoot. You could hit a tree that blocks a secret passage.

Use your blaster more than your other weapons.. it's always a good idea to conserve ammo.

Search every wall, stomp/kick every tile of floor, you never know when a secret will turn up.

On obviously well-designed levels, it's a good idea to backstep after you're near the end, or a place you can't go back from. There might be a secret that a hidden touchplate opened.

Collect all the food you can, it gives you sugar rushes (duh).

Collect all the gems you can... 100 and you get an extra life.

Collect all the ammo you can. I wonder why?

When you see an enemy: Shoot.

If you misunderstood the above, issue a court order for Epic to go directly to your house and explain it to you. Make sure to ask for Tim Sweeny specificly, and don't forget his autograph... ask him to stay a while, he always needs a break-- =]

Be sure to check the news every day, for a new Tip Of The Day! You'll also want to view the old ToDs, for more cool tips!