At 332 pages, 297 are the content.
When trying to get a review or rwo for Ephemeris; I found this one: https://youtu.be/NQS6mRd-
I do agree with most of what he says (Tetsubo57).
Editing: font size ok. Perhaps saved 20-30 pages by condensing some of the example classes shown (possible.)
Combat rounds are 10 seconds long.
Weapons have a damage factor, which is multiplied by the difference between the attack and defence rolls.
The Arbonix to me do seem somewhat wierd, with 2 rows of 'nipples' on their chest to 'float'.
The system shouldn't be too hard to 'home rule' by GMs, if they wish to make changes for their campaign or scenario(s) they are running.
If you prefer using D6 instead of D20 for OGl; Ephemeris should do pretty much ok.
At £4.00/$4.99, it's serviceable.