Thanks for your comment! ^^ I'm glad you liked the game ! :D
Ehh... yeah, the lighthouse guy and the last level are a bit too hard, oops ! :s (not enough time to adjust the difficulty unfortunately ^^')
For the bullet hell patterns, I made some spaghetti code, but here are some basics c: (I'm using Game Maker btw)
For most bullets, I have variables:
-for speed
-for direction
-for acceleration (I multiply the speed by this variable)
-for the change of direction (I add to the direction this variable)
-for min and max speed and direction (in order to constrain the respective variables)
-and a few more, but that's already pretty good ^^
For the bosses themselves :
There's a pattern index variable and a "timer" variable (let's call it 't' xp) that increase each frame.
When t modulo a certain value (depending on the pattern) equals 0, I use usually one or two for loops to spawn the bullets (in circle or in line) with a certain speed, direction, initial position, acceleration, etc... that can depends on t, the 'for' variable, randomness, the player position, idk, it's up to you ^^'
The possibilities are only limited by your imagination ! You can also watch other bullet hell games in order to see the different possibilities (without copying them of course! c:)
When t reaches a certain value (depending on the pattern), the pattern index increases and t resets (:
I hope that's clear enough and that it helped you at least a little bit ^^'