X-Com Apocalypse is an old favourite of mine, and something that I tend to do with my favourite games is to mod them to improve balance and replayability.

I haven't played the game for a long time, but here is a balance mod that I made some time ago. It doesn't have any new enemies or items or anything like that. It just tweaks the research tree and stats of weapons & aliens to make the game a bit more strategically interesting and a bit more challenging.

Here's a short list of some of the changes to give you a sense of what kind of things are changed. A more complete list is included with the mod.

* Alien toxin weapons are now blocked by disruptor shields - just like every other type of weapon. And so disruptor shields are now significantly more useful to the aliens, and significantly more difficult to capture intact!
* Spitters and entropy weapons are now especially powerful against disruptor shields, which makes spitters, multiworms, and hyperworms continue to be a threat in the late game - rather than just becoming cannon-fodder.
* Plasma is also more effective against disruptor shields; making the plasma sword a viable option for cutting down shielded enemies.
* The cost and availability of most vehicles has been adjusted, so that air hawks and interceptors are a bit more viable compared to hover-cars and hover-bikes.
* Anti-alien gas is now unlocked significantly sooner. Previously it was unlocked so late that you've essentially won the game by the time you get it. Now, you'll be able to use it - and make good use of the fact that it can kill aliens without damaging their disruptor shields. (The gas now requires toxin B, and research of a live Skeletoid and Micronoid.)

Anyway, that's it. There are more details included in a text file that comes with the mod. I probably won't update the mod again any time in the near future, but I do think it's high quality enough to share. I hope someone here enjoys it!

(When I did a quick search to find the download link of the mod to post in this thread, and I was pleased to see that my mod has been referred to positively on other sites. So I know at least some people like it.)