Game Elements

I’ve been thinking about what game play elements I can have in to make the game more interesting. I’ve thought of power ups for one, you pick up a “power up” particle and this will increase the score of a particle collected for a specified amount of time, say 10 seconds. I thought at first I could just have them load in at any random time in the song but after a quick think I decided I can’t. The problem is if I’m going to have a scoreboard, everything has to be fair for each different person that plays the level (song), so I can’t have the power up load in 6 times for one person, 3 times for another cause that will drastically affect the scores. So somehow I’ll have to retrieve the song length and somehow average it out and make a power up appear say 5 times randomly within that song. I also thought I can’t have one appear under 15 seconds (5 seconds catching time, 10 seconds increased score time = 15secs) from the end of song. This is because if I give the player 5 seconds to catch it, it will be unfair if the power up appears 3 seconds from the end of the song, giving the player only 3 seconds to catch it and then use it. I also can’t have them appear on screen at the same time because it will be one wasted, in short a headache. I’ve thought of maybe an enemy particle that will do the reverse but the code will be similar to that.