When I used it, we certainly used it as a game engine. In fact I'd say one of its bugger flaws at the time was that it was less capable graphically than more industry standard engines. Seems like it's catching up in that respect.
It was very easy to use if you're familiar with standard dev tooling. Nothing like Unity, but if you know how to use an IDE, you were basically ready to roll.
This is what I immediately thought of when I saw the O3DE post on the front page. "Oh! Is Ogre still a thing?" Sad that other thread wasn't it, glad to see that it is the case, otherwise.
I have higher website standards for any project related to graphics rendering. Ogre's homepage with its white text over the yellow to green gradient background image is a bit of a disappointment. My vision is not bad, but I needed to select to read the text.
GP is talking about the current homepage which shows the following text over a colored background:
> Since 2001, OGRE has grown to become one of the most popular open-source graphics rendering engines, and has been used in a large number of production projects, in such diverse areas as games, simulators, educational software, interactive art, scientific visualisation, and others.
This was my first game engine, before Crysis and then Unity.