As is usually the case, I then spent another hour tinkering with the design and, specifically, finalising how the pertinent information will be displayed; I like the idea of numerical values for certain items (e.g ammunition), but prefer bars for other commodities (such as energy).
With this in mind, the two displays at the top left/right of the screen will display weapons and items, and will feature both numerical displays and representative bars. In contrast, the display at the bottom-right of the screen will have just representative bars, including the player's energy level and the Drone's energy level (the player, as per the C64 version, will be able to capture and control other mechanical Drones during the game).
A bi-product of all the tinkering was the idea to have different colour schemes for the HUD; on the C64 version, each Monitor craft came in a different colour (to give the player the impression they were controlling a new craft after their previous one was destroyed). I've always liked this idea, and I hit upon the idea that each new Monitor craft could come with a HUD colour scheme to match the ship colour. Hmmm!
After a couple of suggestions on the Llamasoft forum, my thoughts returned to yesterday's conundrum: do I restrict the player to the centre of the screen, or allow them to roam freely and - occasionally - disappear behind the HUD? After careful consideration, I decided on the latter. To compensate for situations where this might not be user-friendly, I hit on the idea of using the final HUD area at the bottom-left of the screen as a radar/scanner, which will show the location of key objects/enemies.
My final task for the night was to integrate the new HUD graphics, which seemed to shrink the playing area considerably (or should that be alarmingly?). This was more than a minor bugbear, particularly as I was extremely pleased with the look and feel of the HUD so far. The obvious answer was to expand the screen to 800x600, and after tweaking a few variables and the HUD layout, everything was in, working, and looking pretty dapper.
I rounded off the night by creating a bitmap version of the HUD font and tied this in to the mouse wheel function; now the player can use the wheel to choose a weapon and see the change reflected in the HUD. Though not a permanent addition to the game (I have some ambitious plans for the HUD, specifically some nice animation and movement effects), these simple additions are starting to help a very basic shell feel more like a game.

The new-look status panel, along with Monitor spewing bullets...
