I like Van Vogt's writing. I've read a lot of his stuff and I relate well to it.
(Update: Looking up the history, I find that this was his breakthrough story, published in 1939 in Astounding and was perhaps the first of the Golden Age Era.)
That said, the initial premise of this story is weak. This is an ancient world. It had a civilization, but that is gone, and the one critter left from it runs out of food just as the human explorer ship arrives. Van Vogt is showing no feel for ecosystem here, and the timing. Well...
What is interesting is that the critter, the coeurl, is both powerful and cunning. It figures out what the human explorers are just from the circumstance of their arrival. So, we have an interesting critter springing from a very weak premise.
Technologically there is no concept of remote sensing. Van Vogt is portraying the crew as competent. I like that. But he doesn't indicate that they did any exploring or research before they landed. Interesting how little that was part of SF thinking in the 1930's. And, the mother ship lands on the planet surface. However, he does have good radio communication.
He employs a standard exotic for 30's -- a chlorine-based atmosphere in place of an oxygen-based one -- then, curiously, has his critter ignore it.
He spends a lot of time in the critter's head, and depicts a lot of tension in the critter between wanting to go wild and being a patient cool head. What he does not depict is this creature thinking he can cooperate with these new aliens. He also does not have the crew question early on what this thing eats.
Interesting. He explains this civilization's lack of space travel on their being isolated -- 900LY to the next nearest star, only one planet, and no moon around that planet. Whew! Nearest stars in our area average 4 to 10LY. This means no bright objects in the night sky of this alien planet, either. The Milky Way would be there but distant looking, along with perhaps a handful of somewhat nearby super giants. There would be the same number of galaxies as we see. Truly a dim and uninteresting night sky. Also he has Venus as habitable, and a colonizable destination that comes before Mars. At this writing we are still in the "Venus is a jungle planet"-era. (My solution to this how-to-isolate-a-planet issue is different. I talk about a deeply clouded sky so that surface-dwelling people don't even think of looking upwards and wondering about other worlds.)
Van Vogt does a nice job of mixing in his sciences. His extrapolation of social science, explaining the monster's existence and characteristics, is believable and powerful. The crew's reaction to the science is nicely reasoned.
Umm... as I read on the coeurl gets more interesting. Van Vogt does a really good job of portraying powerful and cunning. He has given the coeurl a wide range of senses and he uses them well. And I like how he handles the crew reactions. Neither side in this contest is stupid. Bravo!
Interesting... because there is no presumption of computer power or computer information, this coeurl doesn't need much information to take over the ship. He just physically heads for the engine room and sets up shop there. Likewise Van Vogt does not mix any robots into this scenario.
An interesting bit of language evolution, Van Vogt calls generators dynamos. Why the term evolved is still a mystery to me.
Nice ending, good science in it. And, again, I loved the way the crew worked together without a lot of drama. I find the interpersonal conflict between good guys that is considered necessary for contemporary stories to be so whiney most of the time. This "we just work together" style is most refreshing.
All-in-all, most satisfying. This is good technofiction. I'll have to add Van Vogt to my list of memorable authors... even though I'd forgotten how memorable he was. <grin>