XCOM: Enemy Unknown

Some tips:
1. Starting continent. Money is very tight at this level of difficulty, so you need to start with the continent that brings in the most income (or close to it). This is Sev. America (+275 dollars) or Africa (+210 dollars). Africa gives you the opportunity to receive 30% more money from each country covered by satellites at the end of the reporting month. Bonus North America is critical for the Ironman regime, because in normal mode on the Impossible, you can make manual saves at the beginning of the month, and by a certain date of UFO arrival, transfer interceptors to the desired continent. But starting in the North. America, you are guaranteed to avoid any country leaving the XCOM project at the end of the first month, because... enough money to buy 4 satellites, an uplink and a workshop.
2. Strategy:
a) Base management. 6 events are planned for the first month (first mission, first abduction, downed UFO, second abduction, consular mission and Council report). On the first mission there are 8 sectoids, each of the fighters needs to kill at least one enemy, it is also advisable to bring the corpses of enemies (use grenades only to weaken enemies, or as a last resort), they will be needed for sale. Upon arrival at the base, we make a save. At the first abduction, we select a country that provides 4 engineers. Upon returning, we sell the corpses and buy 4 companions. No later than March 7, you need to order the construction of a workshop (this is +5 more engineers) and go to the UFO assault, upon return we sell everything. Next comes either a consular mission (I advise you to buy the Slingshot DLC and select it, it’s 200 bucks, 2 engineers, 2 scientists and the Chinese Jang, a very good heavy fighter), or a second abduction, in which we again select 4 engineers. No later than March 17, after the construction of the workshop, we immediately order an uplink (it will be built on March 31, the day of the Council’s report. After its construction, we immediately launch satellites, priority - Africa (if you have a base located in Africa, then any panicking countries, their there will be 4 pieces).
b) Research. Because you will reboot many, many times in tactical mode, then you won’t need armor, at this difficulty if you don’t kill visible enemies in one turn, then they will usually kill you, so priority is laser weapons, which will greatly help during the first terror -mission planned for the second half of April. Therefore, the path is this: Weapon Fragments (8 days) -> Beam Weapons (21 days) after which it is advisable to buy 2 laser rifles (for support and assassin). Next, we’ll explore Heavy Lasers, which will provide us with laser machine guns for heavy vehicles and laser cannons for interceptors. After which you can develop as usual: Alien Materials - Experimental Warfare, etc. You can forget about laser snipers (although laser shotguns are amazingly good, but I lasted without them), in June the Mutons change their light plasmas to assault ones, by this time I recommend getting a camera for interrogations and arc thrower. We grab a muton, put a plasma rifle into research, after which we examine plasma snipers and heavy plasmas, and with this stuff you can storm the alien base (however, it can also be stormed with laser weapons, and the sooner, the easier). During the assault on the base, be sure to capture the sectoid commander.
3. General recommendations. Save-save-save. All events in the global mode (dates of upgrades, UFO arrivals, Council missions) are generated during the Council report (events for the first month are generated when choosing a country to place a base) and remain unchanged until the end of the month, so always make a save on the 1st day of the month, thanks to which You can always replay a given month if you missed the deadline somewhere. If you are not satisfied with the dates of events for the current month, then it is advisable to load a save made before the report, after which the events will be generated differently. Thus, for example, you can save on interceptors - you have replayed the events, found out where the UFO will land/arrive and transported a couple of launch aircraft to this continent, just manage to rearm them in time (first laser or phoenix guns, then plasma). In tactical mode, spamming saves will also save you, especially if you opened a bunch of packs at once during the next turn. While there are only 4 fighters in your squad, under no circumstances open the packs on your own, you risk finding yourself in a hopeless situation (even 2 packs of sectoids will fill you with plasma with your eyes closed, and you won’t even be able to hit them). If you don’t like the map, you can always load an autosave made on the base; the map is selected from the pool during departure (when you confirm it).
4. Composition of fighters. I recommend this: 2 snipers (Squadsight, Damn Good Ground, one Disabling Shot, the other Battle Scanner, Opportunist and Double Tap), 2 heavy (Bullet Swarm, Shredder Rocket, HEAT Ammo, Danger Zone and Rocketeer), shotgun assassin (Tactical Sense) , Lightning Reflexes, Rapid Fire, Close Combat Specialist, Killer Instinct) and support (Sprinter, Field Medic, Rifle Suppression (forget about reviving soldiers, you should not lose anyone, restart if a soldier takes crit damage and remains unconscious), Combat Drugs, Savior).
5. Enemies. Every month the enemies have a new unit - in March you will meet only sectoids and skinny men (if you go through the DLC, you will see one muton or chryssalid in the first mission). In April, a floater appears, in May - a muton, in June - a cyberdisk and drones, in July - a berserker, in August - a heavy floater, in September a sectopod and an elite muton (both can be seen even earlier, they will be part of the Overseer team). The number of enemies on missions is dictated by the difficulty (Difficult or Very Difficult, missions simpler than these, in my opinion, do not come across at all with this skill), these are usually 3-4 packs of 3 enemies in each. Remember, the sooner you start storming the base, the weaker the enemies there will be (at this difficulty there are 28 dudes), the coolest one for me was the lone cyberdisk there.
6. Second Wave. Yes, yes, don’t be afraid to use additional settings when starting this skill, because among them there are not only complicating ones, but also quite interesting ones. I advise you to definitely take Absolutely Critical - guaranteed crit from the flank (an enemy flanked is marked with a yellow shield symbol) and Not Created Equally - random stats for beginners. How do you like a heavy that has an Aim of 80 points at the first rank? Or a sniper with the rank of colonel with the same Aim of 120 units (110 your own and another 10 from SCOPE)? Yes, it is quite possible to get/raise such fighters. But keep in mind that this coin also has a downside, these soldiers may well get low Will (minimum 25 with a norm of 40) and you will have a lot of panickers.

There is a small glitch that makes it a little easier to storm the main alien ship. In the first room, after opening the pack of aliens (commander of sectoids and 2 sectoids), after your move (kill the sectoids), 2 cyberdisks and 4 drones will spawn at the top. This spawn is shown to us by the camera, so when the camera flies to the place where the first plate is supposed to spawn, we don’t wait for it to spawn, we go to the menu and make a save, after which we immediately exit the game. When loading, you will find yourself in the same room with ready-made sectoids and there will be no enemies (except for two more initial sectoids at the far door). I understand that 2 cyberdisks for regiments armed with plasma barrels is not a problem, but still. Works the same in Ironman mode.