Aim direction limit

Please add tag note with the number of identified directions player is limited to.

Examples:
* 1 : only in front, common in auto-scrolling shmups (should only be noted outside of them)
* 2 : left and right, front and back, etc.
* 3: usually left, right and up/forward
* 4 : usually front, left, right, and back
* 5 : left, right, up, and upward diagonals
* 8 : same as above but diagonally too

The above examples are not the only variations possible, but the most common.