WARNING: spoilers below!
Hint #1: Read the game description and look at the letters in bold
Solution: The letters spell out "AVOID THE EXIT"
After collecting all the coins in a level, DON'T head for the exit. Eventually a drone will spawn and try to attack you. Line up the drones attack with the stone blocks - two hits will destroy them. Head down the gap to enter Proto-World
At any point in the stage you can repeatedly jump on the stone blocks to damage them. Eventually they will break.
World 2-2, drop down this pipe
World 4-3, re-enter Pixel Mania! from Proto-World
Take the high road and double back when being chased by the Code Monster
In Proto-World, jump up the hidden blocks either side of this huge tree
In Proto-World, follow this hidden path...
jumping over hidden obstacles as you go. Follow the path up, round and drop down to the Golden Pixel.
In Proto-World, the top right corner, drop down and hit these invisible blocks from below. Then make your way back round and collect the Golden Pixel.
In Proto-World, several NPC (the pink guys) will have food items appear above them when you approach. Find that item and return them with it to complete the quest. All food items are hidden in Proto-World
CODE MONSTER BATTLE
The Code Monster has 3 attack modes; a straight line (SL), aimed (A) and random (R). It always starts with SL before going to either A or R and then back to SL, and so on.
During SL there should be one or two gaps to fit through. The code blocks fired at you block your bullets and don't harm the Code Monster, so staying in the middle of gaps for as long as possible is key. To that end you want to fly as far left as you can to give your self more reaction time.
For A you want to go to the very top of the screen and then after a moment to the very bottom and then back up. This should give you enough time and space to avoid everything. Again flying as far to the left as possible should give you more thinking time.
For R try and stay in the middle and move round in circles avoiding stuff. If possible avoid the edges as this is likely to lead to you being blocked in. As the projectiles are aimed randomly you experience my vary! Good luck!
Play the game normally, until level 4-3.
Collect all the coins and then enter Proto-World
In Proto-World, collect all 11 Gems, complete all 4 fetch quests, and the Golden Pixels
Re-enter Pixel Mania! via the pipe and collect the last Golden Pixel.
Return to Proto-World, purchase the spaceship and destroy the Code Monster.
N.B. The above must be done WITHOUT using any continues.