Pretty good idea
But you need to work on your animation a little more. The audio was great in quality and the message was clear as day, but the animation was what threw me off the most. Throughout the whole thing, Larry's face, his emotion, stayed exactly the same: like he had some small smile tugging at the edges of his lips, despite being depressed like you make him to be. Large lips are something you want to avoid most of the time, unless you know how to draw them properly, and that should only be used on girls who have full lips. Next time, line lips are the way to go.
Also, there was the blinking. It annoyed the shit out of me, seeing him keep on blinking, blinking, blinking, when none of his body even moved throughout pretty much the whole thing. Although blinking is good for realism, you might want to tone down on it a bit, blink only when necessary, put in more eye closing, fading, widening to help the impact.
For the detail you put into Larry and his surroundings, that's the main thing you should work on before you begin your next project. Larry has little emotion and animation in his body, leaving it all in his eyes. His hair is left unshaded and his clothes plain and flat, same with eyes. Larry's head and body seemed too large and out of proportion, and, as I have said a million times and say a million times before because I am a total fucktard, flat. Although you did a nice job on the astronaut part, the rest of the background didn't reel me in, didn't make me feel like I was there, in Larry's shoes. The background was flat as hell and pixelly, which can be easily fixed with just a few tricks you can pick up from tutorials and studying other artists and animators.
The voice-acting that adds to the flaws of this movie. Although the script was well-done, the voice-acting made me think of Batman, who the fuck else. It made me think you had the guy who played Batman do the voice-acting for you. When doing something serious like this, it's good to go for the worn-out voice, but not so gravelly. When I clicked the link to this flash, I'd thought the animation was going to be funny, and, when I heard the acting, I thought the character was going to have this old, gravelly voice to help lift the comedy. Of course, I was wrong.
All in-all, work on your animation and drawing skills by A LOT, but keep up the great audio work, get new voice-actors who aren't actually Batman in disguise, and just keep practicing.