I vividly remember watching this flash animation many years ago, and every now and then I get the urge to go on a hunt for it to no avail. Sometimes I consider the possibility that I actually dreamt it all up, so here's my last resort.
The art style was reminiscent of something like Foster's Home for Imaginary Friends, very clean and simple. It was about a robot boy/teenager that had the ability to time travel by pressing various buttons on his chest. His design was very Mega Man-like with big red boots, gauntlets, a torso with a clock symbol on the center and a partial helmet that revealed a completely human face. He had a human sister, a red head, of about the same age.
The scene I specifically remember involved him fighting a giant bulky robot -- think someone like Bane. He's pinned down and about to get smashed before he begins to rapidly tap the buttons on his chest. After a brief slow-mo segment of the fist nearly reaching his face, we see him blink out of existence.
We get a time card of an alarm clock with a robotic head and a voice over of "6 weeks earlier". He reappears in his sister's room and calls out, "I need your help!" The sister, who was tapping away at her desk, looks briefly surprised before turning around with a smile as she replies, "What can I do for ya?"
We cut to another time card as we return to present day, moments before the robot boy was about to be punched, only to be saved by the intervention of his sister.
Aaaaand that's pretty much what I remember! It's crazy to think I can remember so much about it and not the title but that's exactly why it drives me insane when I can't for the life of me find any trace of it ever existing. If someone here could give me a miracle and figure out what this is, I will love you forever. <3