First Script Idea

I've thought a little bit more about some of the ideas I had, and managed to flesh one of them out somewhat. It's still not entirely strong enough to carry a whole film though, so I'm thinking maybe if I write out a script for it, I'll be able to visualise it a bit better, but I'll still keep trying to think of different ideas in case I can think of a better one, or if this one doesn't work.

So, basically, there's a man who plays the starring role in an extremely cheap and cheesy sci-fi TV programme. The film begins with the crudely animated opening to the series, and then continues on with the episode. At some point our protagonist messes up his lines, at which point we hear the director yelling "CUT!", and the camera pulls back to reveal the set and film crew around them.
We then see the man talking to one of his co-stars about feeling like he's wasting his time working on this terrible show, and that he wants to actually do something with his life. He then sees an advert in the paper for a group of scientists looking for someone to test out a prototype time machine they've made. Our man thinks this is a golden opportunity to do something with his life, and to become the first man to travel through time.
He goes along to the interview, where he's told he will be sent several years forward in time, then when he's there will be sent back to the current time. He agrees, and is sent forward thousands of years into the future. Once there, he finds himself in a field with no traces of mankind or civilization anywhere to be seen. After a brief period wondering where he is and what's happened, a small robot appears on the horizon, running towards him. The robot tells him the scientists who sent him forward are unable to meet him, as the human race has been totally destroyed. The robot tells him (maybe through use of flashbacks?) that the governments of the world began losing more and more money and becoming more hostile towards one another, and withdrew all the money they'd put into scientific research and used it to build up their military, launching into a full scale global war which kills thousands upon thousands of people. The robot was one of the last models made, but due to the lack of funds has been built quite poorly. It's equipped with a device that allows it to see into (or predict) the future, but this doesn't work quite as well as it should, and is always missing a few key facts. The robot, sensing the inevitable destruction of mankind, sent himself forward to meet our protagonist and try and help him head back to his own time, but mistimed his arrival slightly, hence why he was a few minutes late. The robot tells him there is one surviving time machine somewhere on the planet, but he isn't exactly sure where. The man and his new found robot pal must try and find it to send him back, and try and stop the eradication of the human race!

I'm gonna try and have a rough script for this idea ready for the workshop on Monday, but I'm still not totally sure if I will use this idea. I have some thoughts on how to achieve many of the effects I've mentioned here, but I'm not sure whether the plot is solid enough to carry itself, or indeed whether it can do this comfortably within 6 minutes....but I'll give it a go!