I played nearly all X-COM games , and have some Suggestion, perhaps not all is possible.
1. perhaps 2 or 3 more diffrent UFO´s is a bit boring if you capture everytime the same structure (more maps inc., thats good)
2. to spread out the Aliens more diffrent in the different UFOs , mostly all Aliens waiting in the first room behin the entrance and in the Bridge , means why create a UFO with 3 or 4 lvls,if all Aliens everytime in the same 2 rooms ?
3. perhaps you can create 1 or 2 more Alien main races in original UFO we had 5 mainraces in Xenonouts only 3,
and some more Special heavy Units , i liked this 2 leg heavy Robot from original , 3 drohnes in diffrent sizes isnt very innovative
greetings