That was incredibly good. Some of the things I really enjoyed include the way you personified the robot, the cutscenes in between, and the character development of Heather. You've also got me really curious as to what happened to the robot in that long interim in the middle, but I guess that will have to stay a mystery for now. And with the amount of gameplay you put in, it puts a lot of other demos I've seen to shame. I'm looking forward to reviewing this game (I'll put it on my list and keep you posted!)
A few suggestions for things you might want to incorporate:
*More difficulty modes? Some of the later levels took me a few (hundred) times to pass. I had to take a break in the middle, actually. Maybe there could be an "easy" difficulty with more checkpoints? Similarly, you could add a "hardcore" mode to complete the ENTIRE game without any deaths. Too challenging for me personally, but some people enjoy that sort of thing! Maybe skip the tutorial-type levels and make it unlockable after completing the normal one first.
*For the chain-climbing part, I may have missed it but I don't think we were ever told how to do so explicitly? It did take a while to figure out that I was to use the up arrow key to climb up but I did get it.
*Voice acting? Are you planning on recording an actual voice for the robot/other characters? What would seem really cool is if you could start off as the automated computer-type recording and gradually transition to a full human voice as our robot friend "grows up." I don't know if that's feasible, just an idea.
I also commend you for sticking to a project for five years - that can't be easy. Has it been an off-and-on thing, or have you worked on any other projects? In the event you have other games I'm sure those would be fun to play as well. The only sad thing about this is that somehow no one has commented yet...but I hope more people discover it soon! So in conclusion, the answer to your question is no, you're most definitely are not wasting your time with this endeavor. Given how long you've worked on it so far, I will be eagerly awaiting seeing the finished game!