Here's some research I did on Rebelstar Raiders . One thing which I really like about the Rebelstar games is that the moonbases and other installation appears functional. It's not just random mazes and rooms with crates. The first game had 8*8 px characters, and if the maps use tiles it doesn't show at all. The later games (Rebelstar 1 & 2) moved to 16*16 px characters, and then Laser Squad introduced character rotation and an angled perspective (not isometric though). X-Com inherited a lot of combat mechanics fom these older games, an in some ways it was inferior in that department. I think the machinegun fire and aim control works better in Laser Squad. You can spray X number of bullets between two arbitrary points. It feels really Rambo.
Here are a few sheets with unfinished redesigns. The character proportions and head scale are about the same as in the Xexyz stuff.
As for X-Com, I think I'm going to have to revisit my Rebel Squad project and revise the designs. I think these kind of proportions with more curves is more dynamic, and I've changed my mind about real time vs turn based. One of X-Com's biggest strengths is character development, and in a turn based game you can maximize the player's exposure to the characters. I think, even if you design a real time system with multiple monitoring windows (for scattered characters), the player will have a constant nagging feeling of having to be everywhere at the same time with his eyes. It's not enjoyable to constantly be reminded that you might be missing important action pertaining to your characters. Being able to effectively deliver tasty little bits for the player to build his game spanning macro story with takes priority.
As for the cute cartoon style, I don't believe it would make the game less scary or involving. Horror is mostly music and build-up. Benny Hill music will make almost anything funny, and if you just walk into a grimdark scary movie it's not scary at all because you missed the build-up.
Master of Orion 1 is a nice little game which I never had the chance to play until recently. I started on a redesign project a while ago, but decided to go my own way halfway in. I sketched up my own aliens and game mechanics to avoid infringement.
I got distracted as usual and went off to work on something else, so I'm not sure in which state I left this.
MoO1 / Space Conquest
The X-Com genre is terribly neglected, is it not? I was working on this Xexyz (a side view jump and shoot game) redesign project when I totally derailed and turned it into a topdown X-Com game instead. My universe design approach is getting kind of worn. I'm always using the "giant spacewar - defend a base" setup. So, yeah, well, here's another game which will never see the light of day. I'm not sure who sits on the Xexyz licence. It's probably Hudson Soft or Atlus.
Turtle game (Edit: Made another 'screenshot'.)