1. Include an estimate on how much gameplay, in terms of minutes/hours [...]
Based on which criteria ? In Ren'py games with free roaming possibilities, there's people who check every single location every time, and those who goes straight to the point. Same with RPG Maker games there's those who click on every single piece of background just in case there's an object hidden, and those who go directly where they are expected ; without forgetting those who don't have a good sense of direction and get lost every time.
To this, you must add the fact that none native English reader can need more two or three time more time to read the text if their English skill aren't really good. And finally there's all the little things (a VN made with RPG Maker have a shit ton of loading time, a SDD hard Disk while goes way faster than a HDD hard disk).
In conclusion, a game which while take 1 hour to be completed by someone can legitimately need three time more for someone else.
2. [...] including roughly how far along your overall game is, percentage wise or fractionally(e.g., 50% or "halfway done").
5. [...] the pace at which you are actually going to update your game [...]
While the author should know his story from start to end, and the pace he will update it, it's still not reliable.
A whole game take at least one year to be done (most of them do it on their free time), and a lot of things can happen during this time. He can be sick, can be victim of a disaster (natural or not), can have personal issue (someone in his family die, his kid/wife/husband is sick, an increase of works needed at his job, etc.). This will affect either the update pace. It can also affect the game state because the author will finally don't use this or that, kind of rushing the game to its end, to have more free time for his kid/wife/husband by example.
There's also the fact that he can have an idea to increase the content without going outside of his story, and/or can think that adding this fetish can be a good things, and/or discover that that fetish is mostly disliked and want to remove it.
So, once again, it's not a reliable information
3. Include the dev/game's native language, so we can temper our expectations re initial dialogue/writing.
My native language is French. Are you happy now ? Have you been able to adjust your expectations regarding my comment ? Hey have you even had a single clue that I'm a none native English speaker and not just a native English speaker with a bad grammar and poor vocabulary ?
Anyway, what's the matter to know his native language ? It will change nothing to his English skills. There's a lot of Russian games around here, some have a marvelous English version, others can give you headache in less than three lines. Does this mean that all native Russian speakers aren't equal when it come to speak English ? Surprising.
4. Generally, if the game is a linear story, a "linear" tag is likely appropriate. Similarly, if the game is open-ended, "sandbox" might be appropriate. Tags for "minigames", "grinding/upgrading" and "RPG" would be helpful too.
And what when the game start as linear, then include some grinding to finally end as sandbox ? No, it's not stupid, look at recent games made with Ren'py, half of them start in a way, then the author change his mind (or finally learn how to do this/that) and the whole game system change ; everything before "this" update stay as linear, and everything after is now grinding/sandbox/open world/whatever.
In the same time, a lot of games start with a point system, which is finally forgot by the author and the game end kind of linear. There's also the case of those games which look like none linear because they have a lot of choice every two dialog lines, but are in fact fully linear because the said choice don't matter. To know this, you don't just need to play the game, you need to follow each options to look at the difference they make. And what if the choice doesn't matter at first but will change everything in two/three updates, when the story will be fully installed ?
In fact, what you want is that uploaders make a review of the game for you... It's not their task, but it doesn't matter since there's a review system and it's a forum where everyone can comment the game's thread. So, use your eyes and you'll know if the game have or not a lot of content, the average quality of the English, and what kind of game it is. You'll also learn a lot of other things regarding the game, as useful if not even more useful.