I just wanted to throw some ideas out there of ways X-COM 1 could be improved, say if it were remade. These are mainly tweaks and don't include radical game design changes like having 1st person simulator style air combat during interceptions or anything like that.
- first the obvious easy stuff, modernizing the graphics and sound, and improving the A.I. of the aliens where applicable.
- the ability to have a constant real-time view of the graphs of your choice, say on the left side of the screen. I had always used the graphs before, but only recently realized how extremely beneficial the 'alien activity in areas' graph is if checked almost constantly. Clicking back and forth to check it can let you know where every ufo appears around the world and let you at least try to intercept them, although it's a tedious and inelegant method. This is especially helpful at the start of the game as it shows you where the very first ufos appear, and if they're not on the opposite side of the world from your starting base you can get a jump start with a downed ufo within the first couple days.
- a screen that shows total income and expenditure for all bases rather than having to go from base to base to see their monthly upkeep costs.
- the ability to open doors without passing through them However to compensate I'd allow reaction fire from the aliens.
- a graphical overlay on the geoscape showing the radius of each base's radar coverage, to let you know which areas were lacking coverage.
- as the game is currently, if you select a graph then select all the areas or countries, then complete a mission and go back to the graph, everything becomes deselected again. This is annoying. It should save it's previous state.
- remove any exploits currently existing in the game, such as transferring people before the end of the month to avoid paying for them.
- the option of eliminating any aliens that are contained in order to make room for others.
- the ability to 'check' whether it's possible to throw or shoot to a specific spot before having to commit yourself to it. This would especially be useful for throwing grenades before having already equipped and armed them.
- I guess I could just generally say to balance all aspects of the game that could benefit from it, such as improving or toning down various weapons to make them more viable, like the fusion cannons, etc., and balance psi ability in some way so it's not so overwhelmingly powerful in the endgame.
I'm sure there are plenty more nice little tweaks and improvements that I'm missing here. By the way I'm aware of the Xenocide project that's in the works and the forum for it. There's a similar post there discussing possible ways to improve the game; unfortunately it immediately got bogged down with too many off-the-wall suggestions that would require a major programmatical overhaul, like the aforementioned "let's turn all ufo interceptions into 1st person simulator style air combat".