Alright so I'm wanting to start designing a game for Android known as ONESHOT: Tales of the Aether.

Plot:
There is a war against the Corruption, and the Academy is seeking guardians to defend the multiverse against the forces of the corruption spreading across the multiverse. You play as Pantheris and he is trying to save the multiverse by visiting the metrochronatronom or "great clock" (yeah you ratchet and clank fans get some credit here, though it's more like the great metronome rather than the great clock) to get the temporal sword. It's guarded by an ancient clockwork guardian but there is someone else trying to get the sword, and they're not exactly a good person!

Solve puzzles, fight monsters RPG style and defeat the ultimate evil!
YOU ONLY HAVE... ... ONE SHOT.

Now for the visual style, I want something similar to Final Fantasy VII, or FFVII or FF7 or Final Fantasy 7 however you wanna spell it. 2D background, 3D characters, and a whole mess of eye candy for spells, attacks, and opponent defeats.

I want this game to feature heart and art over visual modernization. Gameplay would be solidly developed based on FFVII and limit breaks would be replaced with a new system called BERZERK RAGE. Basically each time you take damage, it fills the RAGE bar, and the attack source can be anything so long as you take damage, so long as you are taking damage. 500HP for level 1 rages, 1,000HP for level 2 rages and so on.
You start with around 500HP for level 1. As you level, via a progression system similar to FFX's and FFXIII's crystalarium system, your HP and other stats will increase, now the level system will be based solely on the character's XP and what you want to spend it on.

I have a very complex and complicated system in mind.

Also there will be shops and chests which have completely random item tables for what the shop will have available and for what the chests will drop.

Character classes are as follows:
Warrior, Berzerker, Monk, Cleric, Battlemagi (comes in Black, White, Blue, Green, Red, and Yellow varieties,) Magi (comes in Black, White, Blue, Green, Red, and Yellow varieties,) Archer, Gunner, Alchemist (comes in Black and White varieties,) Enchanter (comes in Black, White, Blue, Green, Red, and Yellow varieties,) Artificer (comes in Black, White, Blue, Green, Red, and Yellow varieties,) and finally the Brewer (comes in Black and White varieties)

Potion Brewing will be similar to Skyrim/Oblivion where the Identify spell will be your best friend in telling you what ingredients do what and the level of your alchemy skill determines the potency and the duration. Poisons can be applied to weapons and ammo, and potions can be consumed. Also don't forget to cook food for your characters or they won't perform as well as they normally would! ((Yes, in game hunger can be a bitch but I'm implementing it!!! Fuck you haters!))
I'm basically looking for something that would be playable on a PS1 and so therefore would take up as little memory, processing power, and graphics ability on a phone as possible, and won't be so huge as to take up the phone's internal storage too much. Maybe 250-450MB at most, depending on the length of the game. Just remember...

YOU HAVE ONE SHOT!!!