I just went to see Ender's Game. I needed space fight porn so badly - I can't remember when the last film with any space battles come out (Oblivion and Elysium had a little space action but nothing like this). The only thing that comes to mind mind is BSG and that's not a movie. I don't know how someone who never read the book would perceive the movie but if you enjoy space battles and free fall gun fights this can be seen just for that.
I'm well aware of the controversies but I waited for this adaptation for a long time and I wanted to see it. The internet stance on it is mixed (the fandom reviews contain almost nothing but discussion on this in comments) but as I understand he already got paid for the rights to the material so it'd probably do more damage to not buy his books (Ender's Game is back on bestseller's lists) which is something I stopped doing long time ago. Although I cannot claim it was to boycott him. I loved his early books (he was one of my favourite authors when I was in high school) and was big fan but they got progressively worse and worse so I quit even before I learned how insanely bigoted he is and that made me refuse to even touch the drek he spews. However, I will continue to recommend Ender's Game and Speaker for the Dead to people to read (this is what libraries, and internet, are for), not only because I still like these stories but also as an example how vile ideology can destroy good things.
That said, let's go back to the movie itself.
Harrison Ford is perfect as Gruff. This is exactly as I imagined him to be. The scenes between him and Viola Davis' Major Anderson are one of the best moments of the movie that are not battles. So are scenes with him and Ender as Asa Butterfield is great as Ender - lonely and smart and manipulative and survivor. Generally, casting is great and the actors do elevate the material they've been given.
The visuals are astounding - even with Gravity just few weeks away in my memory the zero-gee fights were great and final scenes of space battles were everything I wanted (although I still want more). The Formics' ships and swarming were very well done and human ones reminded me a lot of BSG basestar ship release model. All of them were beautiful. I'm also glad that they decided to stick with 2D. I saw it in IMAX and it looked great (also - teenagers can feel better that the well paid and professionally taken care of young actors still have zits).
If you know the book there is this thing you get at book adaptations - you keep missing stuff that are in the book - there is always that favourite scene that got cut or changed. I'm particularly sad about the Valentine and Peter but almost everyone in Ender's group of friends also gets their story truncated or is completely gone. None of the relationships feel as important as they were in the book. This makes me understand why Peter Jackson made Hobbit into series of movies (even though I still think 3 is a little much). It so much harder to show character growth in two hours when you also want to include space battles (but space battle - so much more cooler on screen).
At the same time, because I read the book, a lot of scenes have bigger importance because you have more information about their impact. When you watch it it feels a little like a checklist of important scenes from Ender Wiggin's life because we run through them so quickly they never have the same emotional impact as when you read it from Ender's perspective (you just see a boy who cries a lot) but I understand why they wanted to keep them because I wanted them in the film too. [Ender's Game spoilers]From the things like "Enemy gate is down" (even if it felt forced) to Valentine convincing Ender to fight back (even though we don't get the layers of them both understanding how manipulative that was and agreeing to that manipulation because of the invasion threat was more important than showing it to adults). I'm happy this was all included even if I only got how important it was because I read the book.
[More spoilers for people who didn't read the book]They also conflated the Command School events with the first Formic planet events so that we see Ender finding the egg after realising he committed xenocide. This is also not that well explained - I'm not sure you get it from the movie that all the kids thought they were just doing simulations for preparation for real battle and not fighting the real war until the end. I'm also not sure how One of the things that makes it such a popular book recommendation is how it makes you believe that the war is necessary and the breaking of Ender and all those kids is necessary to save humanity and then it exposes it all as false. The enormity of the crime Ender has committed (even if unwittingly) and the truth of how unnecessary it was that only he understands (until he writes about it and make himself go from hero to humanity's most hated) is still something that makes this book a great tale. It doesn't quite transfer to the screen.
There are also some little touches - all Wiggin children have different hair colours just like in the book and their father speaks with an accent because he was Polish in the books (although he was brought to US as a kid so he should've lost it but I thought it was nice touch).
Everyone needs to decide for themselves what is the right thing to do here however I'm glad I went to see it. It was fun and maybe if it does well enough there will be more space movies.