Donkey Kong 3/Walkthrough

Blue stage

 * This is your basic greenhouse stage. There are three platforms stacked in a pyramid, so you can roam anywhere throughout the stage for the best shooting position.
 * Stanley always starts in the center directly beneath Donkey Kong, so it's usually a good idea to start jump up immediately and spray Kong a few times before Stanley has to worry about any bug threats.
 * It will take several consecutive shots to convince Kong to climb up the vines considerably. When he is especially high, Stanley is required to jump up and fire or the spray will not hold together by the time it reaches Kong.
 * Remember that while it is wise to destroy Queen Bees as soon as possible, they still pose a threat when you destroy them, so stay directly beneath them when that second shot connects.
 * Be mindful of the flight patterns of the bugs, and don't try to rescue a captured vegetable if trying to rescue it would result in death, or if you're sure that you can force Donkey Kong off the screen before the bug brings the vegetable back to the hive. Any bug holding a vegetable when Kong flees will drop it back to the ground.
 * At higher rounds, pay attention to the sides and force Creepy back up the sides if he is getting too low. If he does manage to reach the platform, you will have to plan your strategy around the times when Creepy is directly beneath Donkey Kong so that you don't end up jumping on him.

Gray stage

 * You won't see it for the first time until round 4 because the first sequence of stages skips this layout.
 * The gray stage is a lot like the blue stage except the middle platform isn't connected all the way across. Worse yet, the place where it's not connected is directly below Donkey Kong. This means you won't be able to charge up the middle right from the start of the level, giving Kong a few precious seconds to slip down the vine.
 * You'll have to move far enough to the left or the right to reach the highest platform before you can return to the center and continue to blast Kong with spray. Other than that, all the strategies of Stage 1 apply to Stage 2.
 * Remember that if you need to drop down from the third platform to the first, it's better to stay alive and make up the time, than to risk Stanley's life if a collision is eminent.

Yellow stage

 * For the full three stage cycle, this is the final showdown between Stanley and Donkey Kong. With no where left to go, Kong must choose between reaching the floor, or having his head forced in to the beehive positioned precariously above his head.
 * Any vegetables that were stolen before now are replenished. In this stage, the insect attacks aren't as constant as the other two, but be prepared for a steady flow of vegetable dives.
 * Instead, Stanley must contend with a pack of Creepies who insist on crawling in Stanley's way and blocking his spray from reaching Donkey Kong. If Stanley's spray does happen to hit a Creepy who is in the way, stop firing immediately and give it time to recover and move on. You can be preemptive about it and attack the Creepies while they are still on the sidelines so they are distracted from interfering with you.
 * In Donkey Kong's desperation, he will take to lobbing coconuts. Donkey Kong will alternate between throwing coconuts at one of the beehives, and throwing one at you.  When you see one drop from the ceiling and in to his hand, stop firing and move Stanley away from his current position and the coconut will sail harmlessly past you.
 * Force Kong to the top and his head will get stuck in the beehive above before the cycle of stages start once more at a harder level.

NES differences

 * There are no Beebombs. When a Beespy, Buzzbee, or Moth escapes with one of your vegetables, it simply disappears.
 * There are no Vine Eaters. When the bonus timer runs out, Donkey Kong simply drops down from the vines and defeats Stanley.
 * Buzzbees replace Beespies beginning at round 9 rather than at round 12.
 * No matter how far you get in the game, Donkey Kong will never lob coconuts at Stanley in the Blue and Gray Stages.
 * Beetles replace Buttiflies beginning at round 12 rather than at round 18.
 * Moths make their first appearance at round 15 rather than at round 24, and subsequently appear in place of the Buzzbees in the Yellow Stages.
 * Bees will only fire stingers while carrying a plant.
 * Plants will always be shown as fully grown. The bonus for successfully defending all 5 plants is always 3000 points.
 * Other than basic sprite simplifications, the rest of the game is very accurate to the arcade versions.