Time Travel

Okay, RPG mechanic time.

A battle system that plays out in "ticks", each tick representing an arbitrarily short amount of time (about a second, but eh). You can move forward and backward through the battle, tick by tick, and assign new commands to your team. So, unlike a normal RPG system, you can rewind the fight a few ticks and have your character heal an ally instead of attacking a foe, and the game will allow this. This means that the ultimate goal in each fight is to find an efficient method of defeating your foes while taking as little damage as possible.

Now, the problem lies in the RNG. Because you can simply rewind and try an action again, it wouldn't behoove us to use an RNG to determine if you hit or not and how much damage you deal and so on. So, the game uses a system wherein the song playing during the fight corresponds with the "tick bar" in a sinusoidal pattern - at the peaks of this pattern, damage and accuracy are increased, while in the valleys attacks are weakened. Different songs have different patterns - "Practice Round", for example, has a very small amplitude and a very long frequency, which results in smaller bonuses and penalties less often. "All or Nothing", on the other hand, has a very large amplitude and an extremely short frequency, which results in frantic battles where attacks alternate between very powerful and very weak. On a final note, the player gets to choose the battle song at the start of a fight except during boss fights.

Also, to spice things up, there is this thing I like to call the "Gambit card" system. Items called Gambit Cards (or just GC) are obtained throughout the game, and allow you to mess with the rules of battle. During a particular tick, you can play a GC to do something like double the damage dealt that tick or poison a creature who starts their turn on that tick. GC's have many uses, and have many durations - many common GC's only last 1 or 2 ticks; the uncommon GC's last about 3 to 5 ticks; and the rarest GC's last about 8 ticks. GC's can also act retroactively or proactively - a retro GC ends its effect on the tick it is played on, but it reaches backwards in time and affects all ticks prior to it until it reaches another GC. A proactive GC works similarly, but it reaches foreward until it reaches another GC. Certain enemies get GC's as well.