Crash Bandicoot/N. Sanity Beach

Crash begins the level washed up on a beach. Head up the path and defeat the crabs by spinning into them or jumping onto them. Make sure to collect the Aku Aku Box. Soon you will come to a vertical climb. Climb up the cliff. You'll find another Aku Aku Box as you climb, and even a box that contains a 1-Up. Here, you enter the second part of the level. Collect the final Aku Aku Box to become invincible for a short time. Cross the passage, defeating the turtles, and breaking the crates. When this is done, you will come to a fork in the road. Choose the path you prefer; before the end of the level, they rejoin. Choosing the one on the right will lead you to a large chasm. Hitting the box with the "!" will make a crate bridge appear. There is a 1-Up in one of the crates.

Getting the gem
Being the first level of the game, it is very easy to pass, but getting the gem is not. At the fork, you will have to follow the left path to the end, then go back and take the one on the right. After creating the bridge of crates, you will have to destroy them one by one, jumping on them without falling into the hole. You can also use the invincibility provided by the three Aku masks and rush to walk across the path of boxes if jumping on each box individually proves too taxing.

Relic
After clearing the level once in the N. Sane Trilogy remake, you will gain access to the time trial version of the level, activated by walking into the stopwatch at the start of the level. Below are some tips to clearing this level as efficiently as possible in order to obtain a Gold or Platinum Relic, which is required for an achievement/trophy.
 * Spin into all three Aku Aku boxes as you progress along the level. Collecting all three not only speeds Crash/Coco up, but also makes getting to the end of the level significantly easier.
 * A time box early into the level floats above a jumping box. The use of this box isn't actually necessary to reach the time box, so if this segment is slowing you down, simply do a jumping spin into the time box once high enough on the incline.
 * Spin into the crab in front of the ruins in order to break the Aku Aku box behind it without any extra effort. While climbing the ruins, jump on the time boxes to propel Crash/Coco upward.
 * After climbing the ruins, break open the third Aku box and run straight to the right path in the fork. Activate the crate bridge and wait a second to simply walk across them while invincibility is still active. While it takes some time for the box path to form, the right path is still significantly quicker than the left, especially if the time bonuses provided by the box path are taken into account.