Hack and slash again. Hooray.
This depth comes with combos. Very shallow combos but combos nonetheless. The Overdrive combos are great for massive amounts of damage but don't keep the game from being just a hack and slash. There are also time freezes you can trigger giving access to a few other moves which also just add to that button mashy feel. Furthermore, Psionics, or your powers kill a lot of things around you and are just make the game too easy.
The first few levels are much too easily accomplished by hopping around and blasting things with a shotgun-like thing exploding hordes of the aliens at once. Bosses are simple after you learn the strategy for killing them but you'll probably be on low health from the hundreds of minions that have thrown themselves at you beforehand. This leaves you on low health, facing a boss and no save point for that stage.
All in all, there's NO SKILL WHATSOEVER involved in the majority of this game. Having a friend walk you to a battle and playing blindfolded will yield the same result as the 'full game experience'.