You could make a randomized level using the 2.2 random trigger, but if you don't have a early 2.2 mod installed, here's how to make a randomized (actually just time based) level. if you don't have trigger knowledge, click the button below this text.
place a spawn trigger, set the spawn group id to 1.
place another spawn trigger, set the group id to 1, set the spawn group id to 2, set the delay to 0.05, check the spawn triggered box, and check the multi-trigger box.
place one more spawn trigger, set the group id to 2, set the spawn group id to 1, check the spawn triggered box, and check the multi-trigger box. This creates a infinite spawn trigger loop.
place a pickup trigger, set the group id to 1, set the item id to 1, set the count to 1, check the spawn triggered box, and check the multi-trigger box. This will make item id 1 forever get 1 item every 50 milliseconds.
place a count block, set the item id 1. Now you can see item id 1 get items every 50 milliseconds.
place a count trigger, set the item id to 1, set the target group id to 3, set the target count to a number bigger than 1, I chose 4. The number you chose decides how many different types of a chunk there are.
place a pickup trigger, set the group id to 3, set the item id to 1, set the count to the count in the count trigger, but type a - first. Since I chose 4, I would press the left arrow until the count reaches -4, then check the spawn triggered box, and check the multi-trigger box. This ensures when the items in item id 1 reaches the count in the count trigger, it resets the items in item id 1 to 0.
place a touch trigger, the the touch group id to 4, and check the toggle on box.
place a ship, or wave portal. Add what ever you want, for a more randomized level, I suggest making atleast 4 in the count trigger, and making mostly straight-fly in the ship section.
After a good bit of ship game play, place a cube portal. This is where the randomized parts of the level begin.
go 12 or more blocks before the cube portal. place what you put in the count trigger at the beginning plus 1 count triggers. So since I put 4 in the count trigger at the beginning, I would place 5 count triggers here. then place the same amount of toggle triggers as the count triggers you just placed. set each toggle trigger to 1 group higher than the last, starting at 5 or above. set the trigger with the lowest group id toggle to toggle on. again, place the same amount of toggle triggers as the count triggers you just placed. set each toggle trigger to 1 group higher than the last, starting at 5 or above. set the trigger with the 2nd lowest group id toggle to toggle on. once again, place the same amount of toggle triggers as the count triggers you just placed. set each toggle trigger to 1 group higher than the last, starting at 5 or above. set the trigger with the 3rd lowest group id toggle to toggle on. repeat this as many as many times as the count triggers you placed. each time the group that is 1 number higher gets the toggle on box checked. I almost forgot, set the first count trigger you placed out of them all in this section to the lowest group all the toggle triggers had. then set the next count trigger you placed in this section to 2nd lowest toggle trigger group. repeat this for every single count trigger in this section each time getting 1 group higher.
then make as many different layouts as the count triggers, then set each layout to the group you want it to be in. this makes a randomized (actually just time based) level. the rest of the level is up to you!
if you plan on adding coins into your level then read the next steps after this. if not, just stop reading these steps.
since the level is randomized you might think you can't add coins, but you actually can! these steps below to add coins are not in the video, they're actually my own way of doing things in GD!
first, figure out where you want each coin in the level to be for each type of chunk.
there is two different ways you can add coins, if you want the move trigger way keep reading until line 20, if you want the collectable way go down to line 22 and read until the end.
now, to remember where you put your coins in each type of chunk I suggest putting a block in the spot where the coin is.
place a coin in a spot somewhere in your level. set the group id to a unused group id.
next place as many move triggers as you placed count triggers for the randomized cube part.
set the 1st move trigger values to move the coin to spot you for the first type of chunk. next set the group id to the lowest of the toggle triggers before. repeat as many times as you placed count triggers for the randomized cube part, each time making the group id 1 bigger and going to the next type of chunk's coin position you marked. set the move time for every move trigger to 0.00, this makes sure the coins move instantly. next move the move triggers to 15 or more blocks before the coin in the chunk type it's set to. repeat this for every coin you put in the level.
Collectable Method
now, to remember where you put your coins in each type of chunk I suggest putting a block in the spot where the coin is.
place a collectable in a spot somewhere in your level.
next check the toggle trigger box. set the toggle trigger group id to a unused group id.
next place a coin at the end of the level, so that the player can always get it if they collect the collectable.
set the group id for the coin to the group id the collect able toggles on.
place a toggle trigger 15 or more blocks before the coin, set the toggle group id to the group id of the coin.
repeat the last 5 steps for as many coins as there are in your level.