Yeah, one of these days I SHALL beat that game, I'm determined! Need it to stop crashing though. Save and save often and hope your save file doesn't get corrupted. UFO has 5 difficulties and I've beaten it on the 3rd, but never bothered to try any harder. TFTD I can barely get far on beginner. I'd find the first alien base, but couldn't ever beat it, especially with the lobster aliens that take like 14 hits to kill.
I realized I had actually gotten
too good at tactical deployment in TFTD. If you breeze through the early missions without significant casualities it chucks the Lobstermen at you when you're still mucking around with Gauss pistols. You want Sonic-blasta rifles for dealing with Lobstermen at least, and ion armor too if you can get it.
It's deeply counterinuitive, but on one of the early missions
get half your squad killed. It buys you much more time to get your troops up to spec, and they're still fairly replaceable early on.
I'm actually in the process of writing up a strategy guide for TFTD at the moment. Probably submit it somewhere that still has the game up, HoTU or something.