It all depends if you're a senior who is applying and you don't have any more tries at the ACT; or if you're junior trying to work their way into applying to the academy. Straight up answer for you is; for the academies; a 25 is not very good. It's above average for all students applying to all schools; but for the academy, it's below both the minimum requirements in certain areas and definitely below the average cadet.
There are 4 good news however; depending.
1. If you are not a senior, you have plenty of time to work on getting better scores. (You want a composite of around 28 or higher), with none of the subjects really below that either. If you look on the academy website, it will mention the minimums. I think 26 or 25 is the minimum in one area, but some require a little higher. (Like math).
2. The academies also take SAT scores. So, you might have done really well on those, and they would take those scores instead.
3. The academies super-score your tests. Which means, they'll take the best scores. So you can take it as many times as you like, and it won't ever hurt you.
4. If you have a kick-butt GPA, class rank, EC's, etc... and the ONLY area you are hurting on is the ACT/SAT; the academy might offer you the prep-school. It's exactly for the student who walks on water, but they have that "1 TOE" that seems to keep getting wet. Maybe All "A's" except that one "C" they always get in Chemistry. Or excellent GPA, but they just can't get the ACT/SAT good.
Anyway; best of luck to you. Learn as much as you can, and keep asking questions. Mike....