In Morphblade you move around a grid slicing, smashing and bursting waves of nasty red bugs. Each tile you move to transforms you into a different weapon: on a Blades hex you can slice enemies on either side of you, on an Arrow you can launch yourself through two enemies in a row.
Turns out Hammer + Hammer was pushing enemies away from your destination when you moved [i]from[/i] it, rather than when you moved to it. Fixed now, thanks to Alfred for the tip.