You can do this on an iPhone by pressing either the right or down arrows, and you can freeze by not pressing anything or a brief period of time.

Do you mean that the gani is different, and that makes it unfair? Would you rather the "idle" gani be used in the event of two or more arrow keys being pressed? That would require the player to stop and continue moving over and over as it is very easy to press more than one key when you aren't thinking about it. On the bright side, an iPhone does not have this problem, as one cardinal direction cannot be pressed at the same time as another. Therefore, the player seamlessly changes direction and virtually covers more distance over a period of time than a PC player would.

In this case, techniques are different, as some things are possible on PC that aren't on iPhone, and some are possible on iPhone that aren't on PC. In my opinion, the general iPhone advantages tend to point towards offensive movement and evasion... But that's just my experience.