Hex editing! I do have to admit that on my first run through the game, I definitely hex-edited my troops to have superpowers, and also loaded a lot when they got killed.
Nowadays I find that taking the punches and considering when to cut losses and retreat is a much more fun way to play. But it is possible to enjoy this game in many ways..
A friend of mine played Terror From The Deep a lot as well, but I think I passed as I heard it had bigger maps that ended up being a bit exhausting, and also being a bit too difficult. The theme is pretty cool, though. I believe OpenXcom also has support for the sequel, and it sounds like it’ll benefit from a little modding even more than the original, so I plan to check it out eventually via OpenXcom.