Anyway, I did get it while it was free, and spent a couple of hours yesterday afternoon playing it. I'm about halfway through the 18th test chamber and stopped partly coz it was time to cook dinner, and partly coz it was making my brain hurt. I don't have much of a sense of spatial awareness, and in computer games rarely think about how maps fit together in 3D space (and am always somewhat surprised when they actually do ...*) so visualising in advance where to put the two ends of the portal so that I get where I'm going is kinda hard. And that's without even thinking about the momentum thing ...
I'd forgotten from watching over J's shoulder just how cute and how deeply disturbed this game is. Like the gun turrets are dead cute, the things they say are sweet and in childish little voices ... and they're out to kill you. "Are you still there?" "Where aaaaaaaare you?" Rat-tat-tat-tat-tat-you're-dead. And of course there's more of that nature still to come. The cake is a lie!
And it's making me want to play more Rockband, Still Alive is one of my favourite Rockband songs :)
*Yeah, really. There are quake 4 maps I'd played for ages ... where I'd suddenly get epiphanies like if you turn right out of there then you get to the place you "get to" by going left a whole bunch of times. Not quite as simple as that, but more like - if you're playing camping grounds and you're at the RL then "the" way to the RG is something like drop to quad, pick up LG, up the stairs, up the jump-pad, round to rail. But actually you could just go to the bridge and do the jump (which I don't think I can actually do in q4, but the point stands). But in my head the bridge was just the way from RL to lower SG (along & drop to RA then down to SG) or one of the ways from HB to RL (up the stairs & over the bridge). The railgun likely features heavily in these belated epiphanies, coz I use it so rarely, but I always early learn all the possible ways to the nearest RL from where I spawn ;) It's like I don't really believe in a game that if you go through a door then you get to the next room, it could be anywhere. So the initial learning of a map doesn't fit it into solid 3D space, it is a network of routes and landmarks that one day gels into a 3D space with a sudden "click" of epiphany.