There's lots of weapons but limited upgrade potential (that I saw, didn't get more than a few hours in) which led me to just find the two weapons I liked and stick with them. I never felt much impetus to change up my weapon setup, since every map is mostly endless streams of non-threatening trash.
The narrator grated on my nerves after about 15 minutes, for two main reasons.
a) It's a massive infodump portrayed with purple prose. "The Kid picked up a Shooter gun, from the famous Shooter Shooty McGee. Man, Shooty McGee was one of the best shooters around. He shot stuff real good with the rest of the shooters." a.k.a. "Revolver get!"
b) Narractor McJazzman feels the need to tell you what you're doing, as you do it, all the time. Get attacked? Narrator. Train's slowing down, sparks are flying off it, enemies are attacking it? Narrator has to tell you all that stuff. Switch weapons? Thank god someone told me I switched weapons. This added nothing but background noise and could have been skipped entirely.
There were a few good parts, but picking out the relevant stuff amid the background fluff desensitized me quickly. They would have been better off cutting the narration in half, making more engaging gameplay, and not encrypting all the background lore in purple prose.
The art was vibrant, which was a good change, and the music was pretty good (but so was Mass Effect 3's, and look what it got). I regret buying any game I can't make myself at least finish once, so... I do regret buying Bastion.