Where the main character in Kick-Ass is a young man driven by naivete and a love of comic books, the main character in Super (Frank, played by Rainn Wilson) is an idiot and a psychopath. He is driven by the loss of his wife and delusional visions which he believes are from God. The religious angle is weird and disturbing, though Nathan Fillion is pretty great as The Holy Avenger. The wife plotline is what really drives the story, and it is also pretty disturbing. Liv Tyler plays Sarah, who is more of a plot device than a character.
Where the female sidekick in Kick-Ass is a young girl brainwashed by her father, disturbed but basically a good person, the female sidekick in Super (Libbie, played by Ellen Page) is, like Frank, an idiot and a psychopath. Worse than that, her character is an obvious male fantasy - a beautiful comic-book-nerd who is always horny and is apparently attracted to ugly guys and violence. Kick-Ass's Hit Girl is also sexualized and hyper-violent, but somehow in a less disturbing way.
Super's villain is Jacques (Kevin Bacon) as a really slimy drug lord and owner of a strip club. His might be the best character in the film as far as consistency and believability. His henchmen are incompetent idiots, but Jacques himself is just a low-life with power and money looking to get more of the same.
The worst part of Super - even worse than most of the characters being idiotic psychopaths - is the utter lack of plausibility. Kick-Ass avoids this problem by being conspicuously over-the-top - it is clearly more fantasy than reality. Super, though, tries to stay real but fails. The main character drives around in his own car while beating people up, and no one ever gets the license plate. The two main characters sit around in broad daylight for long periods of time and no one calls the cops. There is a pitched battle with dozens of gunshots and explosions, but the police never show up. The idiot henchmen kill a cop in the main character's house, and it is never mentioned again.
Super earns its R rating for gory violence, brief nudity, and a fair amount of drug use. It also features three rape scenes (though one of those is in a vision) including a female raping a male.
Mako Mori: Fail
What are these?