The very first thing you need to know about Saki - The Memories Of Summer (夏日祭) is that it's fully translated Chinese doujin VN. You can download the translated version here:
(Use the mediafire mirror).
Mad props to the trooper who translated it all by himself (apparently).
It's a game by fans for fans and you should keep that in mind when judging it.
The production values are fairly decent all things considered. Some of the sprites - like Ako's or Tacos', which is very amusing because they only have cameo roles in the game - are simply great and wouldn't look out of place place in a commercial release. Others - like Nodoka's or Kuro's, which again is fairly amusing because Kuro has her own route with 3 endings - are far worse. Some of the backgrounds look spectacular, but there are also two which are more half assed. The CGs are very uneven and generally bad. The music is decent but forgettable.
The game isn't voiced for obvious reasons but thanks to that you can read it faster. For the first time ever I used the 'auto read' option. You can adjust both the speed of that as well as how fast the text appears on screen so it's possible to find your ideal pacing. Pretty nice for a doujin release. Unfortunately the skip system is a little flawed and you should be careful when using it as it can skip unread text at times.
The translation reads well. It contains a small mistake or two (more like typos, or tiny grammar hiccups) but it looks pretty solid overall.
The VN has a bit of doujin feel to it, in a bad sense. At times the characters act out of character but generally I felt their personalities matched with what I've seen/read in the anime/manga (aside from the Kuro route maybe, which is kinda crap). The pacing is kinda all over the place - at times the game spends a lot of time on fairly mundane, everyday-life kinda stuff and yet some dramatic scenes with confessions and stuff like that are really rushed.
The game offers fan made explanations for stuff that has yet to be explained in manga, most notably Goldfish. I thought it was handled fairly well and made a lot of sense, despite the supernatural nature of it. Tying Toki into the entire thing was a bit much but aside from that I don't have many complaints here.
Despite all the bad things I've said so far I liked the VN a lot. It's not exactly the best thing since sliced bread and you shouldn't expect that. But if you're a fan of the franchise you're likely to enjoy this. I mean come on, it's a yuri (didn't I mention that before? well, that's because it goes without saying!) VN with several routes and Teru as the protagonist. What's not to like?
The game has a Saki route (4 endings, 2 bad without story, one normal, one good) - which is basically the main route of the game, really - an Awai route (good ending only), a Toki route (which is kinda puzzling and I felt bad for Ryuuka but yeah; bad end and good end), a Kuro route (NOW that is some crack!; bd end, good end, true end) and a bit of a hidden route which you can only complete after you go through the other routes. Saki and Awai routes are pretty good and I liked them. Toki was okay but I kept thinking about Ryuuka. Kuro was as nonsense as I expected it to be. Hidden route was just authors having a bit of fun.
You'll probably want to use a guide but generally the rule is of thumb is 'to get a better end go through the VN again using the exact same choices'. Anyway, here's the walkthrough:
So yeah, if you like Saki I say give this a shot. You're not guaranteed to like it and you'd be justified in having a negative attitude towards it but if the pandering will hit your sweet spot you're likely to have some fun. I did.