Birthday Simon Puzzle Box

Inspired by the “reverse geocache” box, I’m working on building an Arduino puzzle box using a SIMON game (you know, the one where you have to repeat the sequence the computer gives you.)

I found Dave Auld’s great example online, and I’m trying to recreate it. I’ve got most of it figured out, but I’m having some trouble with the circuit schematic, especially since I’m not using a breadboard.

I understand all the LCD wiring, but I’m not sure what’s happening between the +5V, GND, and the pushbuttons/LEDs. Would each LED/pushbutton have a ground wire going back to the GND pin? And does one of the speaker terminals have both +5V and GND connected to it?