Implement inverse battles (introduced in Generation VI).

This is a minor issue, but still an annoying one.

Weather particles such as hail currently just takes account of a sky height variable. This is a crude method and would be much better to be replaced with a proper map of depth for each background.

Pokémon who have learned special moves (such as event moves they would not normally learn) should be able to relearn them through a move relearner, should they be forgotten. Perhaps each Pokémon should keep track of every move they have learnt?

All move effects should be contained within Moves.js, rather than having any specific code attached in the main engine.

At the moment, the textbox simply crops any text more than two lines long. It should instead let the player scroll through them, line by line.

Battles with multiple trainers on each side currently do not function properly.

Pokémon should be able to Mega Evolve.

See if there are any better ways (or names) for this functionality.

There should be a setting that allows players in single-player games to switch out their Pokémon in anticipation of the opponent's.

Battle backgrounds could be made a lot more dynamic through forming puddles, reflections in ice, leaves blowing around, etc.

Rotation battles, such as those in Generation VI, should be added.

AI trainers should use different techniques (including using items, switching out, etc.) depending on their trainer type. For example, Gym Leaders should be better at using moves than Bug Catchers.

For some calculations like capture rate and damage, values are not rounded to the nearest 1/4096 when they would be due to hardware capabilities in the original games.

There's currently no support for O-Powers in the battle system. (They may not even be desired.)

Instead of simply filtering out NoPokemon in every instance, it could act like the nil object in Objective-C and simply absorb function calls.

A red/cyan anaglyph 3D mode would be fun and would enhance the visual effects in battles. It also shouldn't be too difficult to implement.

There are a few issues (mainly with the text and the appearance of Pokémon) in wild battles at the moment.

There should be a better system to make use of different Pokémon's positions, instead of using values that "look about right".

These functions were made a long time ago, and I have suspicions they may need restructuring to improve them and fit them in with the current general style of the system.

Move effects other than the default "use" cannot have animations attached to them (for example, the trap effect for Wrap), but one often would like an animation for these.

Pokémon who use Transform will take on the catch rate of the Pokémon they have transformed into. They should instead keep the catch rate of their original species.

For move animations to be completely fully-featured, there are a number of features that need to be added.

• Transformation (translation, scaling, rotation) of Pokémon
• Scaling of Pokémon in each direction independently
• Transformation (translation, scaling, rotation) of the viewport
• Particle effects
• Sound effects (using both custom move-specific sounds and the Pokémon's cries)
• Background changes and foreground overlays
• Pokémon masking and duplication (such as fading to completely white, or making copies of itself for moves such as Double Team)

Transform will ignore the IVs of the targeted Pokémon, meaning it does not copy the stats properly. The other Pokémon's gender is also ignored at the moment.

AI trainers should be able to use items and switch out, just like the player.

There should be a mechanism for Dark Grass that triggers wild double battles and also has slightly different calculations for catch rates, etc.

Sometimes this is desired (such as with Fly), but most of the time, it'd be useful to reset Pokémon display properties. This could instead be a feature of a visual animation editor, rather than a battle system feature, however.

The View properties angle and zoom are currently not taken into account whatsoever.

The Safari Zone uses markedly different mechanics from normal battles, but the battle system should be able to take care of them.

This is obviously undesired behaviour.

Moves that induce effects on Pokémon will continue having their effect event after the Pokémon switches out.

Currently move transitions are long-winded to write out. It'd be nice to have a shorter way to write them.

Implement horde battle (as in Generation VI).

Sky battles, like in the Generation VI games, would be nice to have (and likely not difficult to add).

A local, hotseat multiplayer option would be quite nice to have.

All item effects should be contained within Item.js, rather than having any specific code attached in the main engine.

Experience is currently gained by just the currently-battling opponents to the fainting Pokémon.

The functions in Battle.draw should possibly be moved to a different file, to separate the functionality of battles from their appearance.

This would bring instant display changes up to speed with transitions.

One should be able to use the keyboard completely, instead of (or as well as) the mouse.

As in Generation V, Pokémon should be able to animate at all times during a battle.

In many cases, attributes (for Pokémon, for example) are calculated on-the-fly each time they are used, when they could be calculated at certain points (at the beginning of a battle, for instance) and save time during the actual battle.

One would often like animations for moves like Surf to affect every target into account.

If Pokémon rotate to angles other than very small ones (such as flipping upside-down completely), their positions mess up.

Some moves, if they have an effect over multiple turns, should fail if used multiple times in a row.

The move Metronome does not work properly. Its actual functionality in-game should be looked at so this system's version reflects the actual games' implementation.

Spectating other people's online battles (both live and after the event) would be nice. This feature is probably going to be needed for online battles anyway (for the server).

If Time.framerate is changed, are any timing operations affected? Only the refresh rate of the game should be changed.

If the Pokémon another had targeted has fainted, the attacker should attempt to use their move intelligently on a different Pokémon. Note that this does not apply if their target has simply disappeared using Fly, etc.

There are quite a few comments of the form //? and /*? that describe problems in the code that have not been logged as issues of their own.