Within a Deep Forest walkthrough by Oddity

''Source: http://jayisgames.com/archives/2006/05/within_a_deep_forest.php by Oddity. Corrections and formatting changes added for this wiki.''

Here are the locations of the nine ball upgrades. Three additional levels – Crystalline, Utopioca Minor, and Strange Place – aren't necessary, but do provide helpful hints.
 * 1) Finish the tutorial!
 * 2) Normal Ball - Pinewood Heights, Eastern Side. At one point along the way, you'll be using the updraft from a lava pool.
 * 3) Iron Ball - Shinock Reign. Climb the tower on the Western Side of Pinewood Heights.
 * 4) Speed Ball - That Hover Thing. Climb the pillars a screen west of the Eastern Side save point.
 * 5) Glass Ball - Markstone Ridgemine. Use the Iron Ball to break through the ground two screens west of the base of the tower.
 * 6) Yoga Ball - Ljus / Utopioca. Use the Iron Ball to pass through the windy cave on the mountain's west side.
 * 7) Pathetic Ball - Crystal Path. Use the Yoga Ball to reach the opening two screens west of the Eastern Side save point.
 * 8) Jump Ball - Lunar Cheese Extraction Facility. One screen above the Western Side save point, trigger a switch using the Yoga Ball.
 * 9) Cold Ball - Shadowlands. Using the Jump Ball, fall into the pit two screens west of the Eastern Side save point, then go one screen east. Fall into the pit on the other side of the screen.
 * 10) Free Ball - The Future. Using the Cold Ball, fall into the pit one screen east of the Western Side save point, then go one screen west. Enter the time machine.

Finishing the game
Underwater Lab. Using the Pathetic Ball, fall into the pit on the same screen as the Eastern Side save point and pass the tiger. Start from two screens above the Eastern Side save point.

"Secrets Levels.exe"?
Search the Harara Mountains and the Shadowlands for two four-digit combinations. By now, you'll know where to input them.