LOL. Possibly overkill for this:

I've been playing the game on normal keyboards for years, so any nods towards an ergonomic splay will be nothing but helpful. I suppose it's ever so slightly closer together than a full size board, but toeing in the layout makes up for that. Wrist-wise, I hover. It's literally the one good typing habit that "stuck" from when I was a youngling. I have never had any issues or needed wrist rests, so front-height being 7-12mm taller than most of my boards is not an issue.

If there is an issue it's that the thumb keys are tucked in a bit aggressively to keep a 60% keyboard's footprint, but since this is a very different control paradigm than an FPS or even a Minecraft, and definitely not for typing, it shouldn't be significant problem.

Besides, ergonomic deficiencies play into the immersion and aesthetic. ;-)

must be tricky to hit all those center buttons under your legs like that

This is probably the densest one-stop shop for handwiring resources. It has links to some of the other tools I used, and QMK is the open source firmware that runs many of them (I used a fork that enables a better graphical key mapper), though there are others that can be easier to set up.

On Youtube, there's a kid who has made a cottage industry out of these. Search for Joe Scotto.

In general, searching for "hand wired keyboard" will bring up a lot of resources. Then, if you're so inclined, learn how to do a basic PCB in KiCAD and you start closing in on a device that works every bit as well as a commercial product.

You should try it again. They've added a lot of content, a few QoL features, and made a few balancing tweaks, but even back then the engine was pretty simple and solid.

Oh, it's a lot of fun, and once you get the hang of it it's very easy to jump in for a casual session, or come back to after a layoff, but at the same time it often gets that "one more mission" or "one more custom loadout" time-murderer vibe. The main campaign for humans is a bit on rails, but it's very well-written for a game like this. It is funny to hit a dead end in other mini-campaigns where it's like, "Uhhh, that's all we've written so far. Knock yourself out!."

They came in a large bag of random keycaps from Signature Plastics, one of the "big-two" western keycap manufacturers, but they're obviously relegendable, and I think they're the F10 profile like my "COMMS" cluster.