Yes, there's a 25 minute time limit on the test as a whole. I just recalled the part where they said there was no bonus for finishing fast.

So it probably bakes in a range. Like if you complete this test in the allotted time, you will be in this range. But if you completed it in half the time, you'd probably be higher, but they haven't calculated the range you'd be in. They'd just say, "Yeah, you're in the top range".

It probably never makes sense not to use the whole 25 minutes. If you think you got all of them right in less than that time, it pays to use the remaining time to double-check your answers. The test seems to be calibrated such that if you get all the questions right, and use exactly 25 minutes, you score the maximum, 145.

I clicked finish (without having finished every question) with 2-3 minutes left, and they popped up a dialog suggesting I use the extra time to review my answers (not to keep trying on the question I gave up on).