One way would be to reduce the number of frames in the animations
Another way would be to reduce the amount of animations
Another way would be to reduce the size of the animation-frames (by cropping them?)
Question is, what options are you prepared to look at?
the character fits nicely on a 64x64 tile.
In general i would much prefer using the character and all the animations as a 3D model using Q3D plugin or similar. But not sure how well this one works on Android, iOS, Windows phone as an app, so I don't have to worry about rendering sprites in all the directions, and placing this character on a 2D isometric background.
Besides from that..... what I actually could do.
* Limit running directions to 8
* Reduce run cycle animation frames (not preferred i want smooth animations with a lot of frames)
* Downsize or crop the frames would be the most preferred option as I could quadruple the animations going from 64x64 pixel frames to 32x32 pixel frames, but i'm not really in to Pixel graphics. (character in my avatar is what will be used)
The walking/aiming animation i don't really wanna reduce the number of angles, as it would feel "steppy". It's quite crucial that the animations looks and feels smooth, i don't want to restrict any movement or aiming to 8 directions for example, as it's a precission/skill based game.
for the whole feel of the game, smooth animations are preferred.
I'm leaning towards trying out Q3D plugin for the character, but not if it would export well as an app on mobile phones.