Depends on your goal. For example:
- High risk high rewards power up - they are either hard to take and you need to make a bold move to catch them or the item have a huge downside and upside (like a powerup that doubles your points but also the speed of the game).
- Modifiers - same as powerup, but you chose at the begining of your game how to alterate it.
- Reverse/Static platforms .
- Every X amount of points the game "biom" changes.
- Ball change color depending on the platforms move direction.
- Progression system/End goal - the more you play, the more customization/upgrades you open up.
- ...
And so on. Chose a direcion for the game and do some reseach for similar games on the market, you will be shocked how much now concepts you will find from that. Good luck.