I played Z in my younger years, I was 15 or 16 at that time. Because of lack of any manual I had problems with the strategy which units to build, and so I got into heavy problems after level 5 or 6.
Eventually some years later I did another try, this time a friend of mine showed me some tricks and I got with some effort to level 9. But boy, you’ll turn your hair grey when trying to manage everything in time. It is fast and stresses every brain cell. I wished for a quick save/load more than once.

Every some years I try it again, every time I loose interest after level 9 or 10 because of the immense difficulty. I play the German DOS version (from Gold Games 2) of course, which still runs fine. :)

Gods is very difficult. You can do it with a walkthrough (which tells you which modifications from the store are needed for a level) and about 20 or 30 tries per level. The point is, one time gone too far, triggered a switch too many etc. and you can start again … But I liked it because it was a slow platformer. There is no running, no intense jumping. You need to plan ahead and you only get one chance. Somehow it still looks good nowadays. :)

Xenon 2 was easy. Really it is easy. You need some experience which weapons to buy, then the third level is the most difficult, but not too hard. At the beginning of level 4 you gain an invulnerability shield (kind of a soap bubble) and the rest is piece of cake. I never played it without the bubble, though.

Hi, set Z95 (Antares WinXP Installer) to slow and hard, then it plays very much like the old DOS version, apart from the gameplay modifications introduced with Z95, such as increasing the maximum number of units to 50. Try to build the best units possible, establish bridgeheads, and move forward. You will find that the unit maximum can be your friend... Otherwise, it sometimes also is a good idea to destroy bridges or factories that would be too difficult to defend. Cheers.