What does the demo show you exactly? Because I only played the full game.
Yeah, a large part of the game is the fighting with various groups of enemies, but there really is quite enough variation throughout the game to keep it interesting. The melee battles with your siblings are just a part of the game, if a major one. I won't spoil things too much but there are 3-4 very different areas (one of them I liked VERY much) that feature a quite different style of play involving sharpshooting, dodging and other stuff.
I won't deny the linearity. But the game is short-ish at 3 hours (still not as short as many AAA titles of 50e in comparison tho) and because of that it doesn't overstay its welcome with the melee system, the crazy world, wonderful character design and intriguing story (it's actually more of a step-up to a greater story, but quite interesting on its own).
Might post some screens later.

If it ever is down at 5-7€ again, it's worth the purchase. I wouldn't buy it at 15e either, but that's mostly because I'm a cheap bastard.
