Blood Splattered Innocent
I enjoy your concept of making Pico your traumatized, Blood Splattered Innocent than the Sociopath Hero he really is. The departure from the original game is actually pretty well played, since I can see that this would have most probably happened should Pico have been in a less Tom Fulp inspired environment, I'm pretty sure he would've ended up deeply regretful of it other than his canon What the Hell Hero? attitude. The sad tone of him being so regretful of his supposed crime is, however, not as good as the concept.
Why, you may ask? There really wasn't enough reinforcement of just how sorry he was that he killed all the kids deserving of death by his hand. All you did was portray regretful memories in the form of flashbacks from the original game, with absolutely no "present time and place" reinforcements like for example Pico meeting up with one of the survivors or some sort of hero memorial he thinks he doesn't deserve. The mental anguish is pretty realistic, though portraying it with his memories makes it weak.
The art style is fitting, but since most of the length was spend with him being in his day job sourly reminiscing about the April 30 of decades past, I can't really say that I was very moved by his Memory Lane Trip given what I said above. The music choice was pretty good for the sad theme of the flash, but since there are no high points but only a single monotone tune that kinda killed the position for either a lifter or a downer finisher to what would be the last April 30 that Pico has to go through ever again which could have been remedied by adding a second or possibly even third soundtrack to give stronger difference in between scenes--or int his case if you even had a different scene.
Speaking of endings, the ending you chose of just him being rainsoaked while walking to the only car left in the parking lot (quite obviously his) was pretty weak. I would've liked it better should he had at least somebody else or some old classmates that survived the shoot-out/hostile takeover (excluding Darnell and Nene, they would obviously remember him) actually greet him and to some extent, extend their gratitude or indifference to his trauma. The ending would have been better should you have put a definitive end to the April 30 of his life or added some redemption or further loss to his situation rather than just being alone.
Good attempt, you need tweaking with the key elements such as music choice/s, additional character, reinforcement for his current state of depression, some additional symbolic scenes and of course a better ending than this one. I sincerely hope you come up with a better flash than this next year, and please, change the title to one without equal signs and use spaces next time. I have absolutely no idea how the submission process works, but I trust that you can fix the problem.