It might be worth telling people how big the file is, and roughly how long they will need to invest if they are to play through it to review it. It's not a particularly short game, if I remember correctly.
It might also be worth making a complete single file to download with everything that they need for this purpose. Nothing more irritating to some than having to figure out which files are needed just to get started with the game.
In fact, I can do the time requirement and give a kind of "pre-game" review.
Looking through the LPs and making a rough calculation: The first one is over 11 hours long. That's quite long. In comparison to most games today, that's really long. Your own LP, however, is incredibly long at over 30 hours. I'm not going to watch them to see whether you are just taking your time or are getting through at a reasonable pace.
No matter which of those two it is, it's way too long, even for a hard core gamer. You'd have to have some amazing game design and writing in there to keep someone hooked for even a few hours. And at 50% done? I'm not surprised you feel like taking breaks, and why it's taken 4 years to get this far. That's well over 60 hours, if you just double up the current play time. I'd expect to play a game for that long if I'm done with the story, and am max-statting for sake of it, or perhaps there's a really badass super boss in there to beat.
And if those early maps and designs aren't that great by your own judgement, I don't know whether you will get someone to give you the type of review you want. If you know those areas aren't greatly designed, you need to go back and redesign them now rather than at the end.
I can understand that you can be passionate enough about a hobby to spend a lot of time on it, even if it's just for personal satisfaction. If you are wanting other people to play it, though, I think outside of a few TF fans who wear rosier-than-rose-tinted glasses, you aren't going to see the results you want.
Maybe it would be an idea to split the game up into volumes. It's possible even in RM2k3 to transfer save files from one project to another to continue with the next volume. Each volume would begin with a recap of the story so far so that people can enjoy the game even if they jump in at a later volume. Expecting someone to play through a potential 60 hours of game, just to finish it, is just not realistic. You, the aforementioned fans, and maybe close friends who care about you enough not to be too critical, might do it because you/they are playing with bias.
That's my review and thoughts, before I'd even consider playing.
If you are enjoying the process of making the game, though, then more power to you. Nothing more important than a love for your own creations.