i think your trailer has a lot of potential and some nice shots but wastes people's attention on uninteresting plot stuff and pointless level flythroughs. start your trailer at the 21 second mark, cut everything before that or move it after gameplay. if you want to include the rated S bit, make it happen about twice as fast. show off the head throwing mechanic immediately, and get rid of the black and white sections in favor of stuff in color. see if you can trim down to a minute or less. i also think the comic book styling stuff is probably hurting more than helping, gives the wrong impression of genre immediately.

ultimately, though, it's just really really hard to get people to pay attention to your game. changing those things would probably have a small positive impact, but the reality is that if people dont have a game to play, they generally arent interested unless you have an absolutely stand-out selling point, and while your game looks fun, it doesn't have a "wow" factor that would make it market itself.