Greetings to Everyone;
firstoff, grats to Chris and the rest of the Xenonauts 1 team for making a great game. Also thanks for making mods in the game easy - Chris mentioned in his retrospect on making Xenonauts 1 that it was essentially impossible to make the successor to X-Com people were hoping for, since the interpretations of what that should look like were so vastly divergent. Mods are the perfect solution for that.
Following are a few thoughts from someone who looks forward to Xenonauts 2.
1.) Minimap Please
Someone else probably already posted this, but it would be really nice if you could switch to a minimap view of the area, or just zoom out to see the entire map.
2.) Alien Strategic AI
Reading through some of the posts here Chris already seems to have a similar idea in mind anyways. What i originally wrote was more intended for a similar strategic approach as Xenonauts 1 had, but now there's talk of a different approach, so this may no longer be applicable to the new game that the Goldhawk crew have in mind.
There have been some comments about that Xenonauts ends up being really easy endgame if you had good successes early game. That is kind of in the nature of the game - consecutive successes give consecutive advantages, meaning that if the game has a static balancing this result is unavoidable. One could of course adapt the alien strength to the forces available to the human player, but then it kind of feels like you've been cheated out of your achievement: it doesn't really matter how well you do, the difficulty of the battles you face will always be the same.
So i suggest the following solution: give the aliens a very basic strategic AI, making informed decisions based on last months happenings. Ultimately, the goal of the aliens is to invade and colonize Earth. To do so they (in Xenonauts 1) need to adapt their ships to Earths conditions - once they have done so with their heaviest ships, defense becomes untenable.
The aliens have a specific amount of resources available to them every month, and what they spend it on depends on how last month went for them. If all UFOs they sent have been shot down, they will invest resources into fighter escorts for their UFOs, if their ground forces have been defeated, they will commit more elite troops, if the Xenonauts have been a nuisance, they will start a search and destroy mission against one of their bases, or if that fails execute a terror mission against civillian targets in retaliation. All remaining resources go into increasing the size of UFOs that will be sent down / a doom counter that ends the game when it reaches a certain value. Basically they want to study Earth and humans, and take the place as intact as possible: doing a terror mission would be retarded if so far all enemies have folded before them anyways.
The result of this is that the player constantly faces a changing strategic situation. The player gets to choose in what area he wants to have superiority for a little while. Researched better missiles for your interceptors? Awesome, you'll have a month where you can down UFOs easily, then they'll start sending fighter cover with all following UFOs (forever, until the end of the game), so you either need to invest even more into retaining air superiority, which the aliens will one month later answer with more and stronger alien fighter craft, or you can choose to not escalate the air war, and instead attack UFOs after they have landed. Wasted all aliens without loosing a man? You'll have better troops and no recruitment costs, but on the next ship there will be less alien civillian technicians and scientists, and more shock troops to protect them.
(For this all to work, it would be neccessary that EVERY UFO except fighter patrols lands eventually and stays landed for about 24 hours, so that if the air war escalated to a point where the player simply cannot shoot down UFOs anymore, he still gets a chance to fight. I would even go further and suggest that landed UFOs always show up on the global map regardless of radar ranges, representing ground forces informing you of the location. During this time the alien fighter escorts would retreat to space for refuel and rearm, giving you a chance to land ground forces in a helo ... of course they will be facing an intact landed UFO with full crew.)
Of course you can play dead fish in the water and do as little as possible to only fullfill your current objectives and advance towards the final mission - i'd even suggest that to be the easiest route to win the game. However while you do nothing, civillian casualties skyrocket, nations will cut their funding because they received no aid from you, and you will be cutting it REALLY close with the doom clock.
Here is a bit of pseudo-code on how this could be implemented.
AlienStrategicAI
{
monthlyresources = monthlyresources + 1500 + 100*monthcounter + 10*numberSuccessfulGroundmissions;
escorteffectiveness = ((numberFailedUFOmissions / numberUFOmissions) + (numberShotdownUFOs / numberShotdownInterceptors))/2;
if (escorteffectiveness < 0.5 + random()*0.2)
escortprobability = escortprobability + 0.2 + random();
/*Our UFOs are shot down before they can do anything. Increase the probability of "purchasing" fighter escorts for further missions by this value. Values > 1 mean that there will be at least 1 escort, and there is a chance of additional escorts. This will of course increase the price of any further UFOs "purchased" to do missions. (It would also make sense to increase the probability of air superiourity missions based on this value, but that is not factored in here.)*/
//budgetPs will be percentages of available resources. All numbers refer to last month only, not total since the start of the game.
infantrybudgetP = ((numberSuccessfulGroundmissions / numberGroundmissions) + (3*numberDeadAliens / (numberIncapacitatedXenonauts + 4*numberDisabledXenonautvehicles)))/2; /*This assumes the aliens think of a Xenonaut who fell unconcious but survived the mission as a casualty.*/
baseattackbudgetP = ((numberFailedUFOmissions / numberUFOmissions) + (numberSuccessfulGroundmissions / numberGroundmissions))/2;
terrorbudgetP = numberFailedBaseAttacks/10; /*This assumes no more than 10 base-attack-missions per month. The expectation is that by the time you would reach 10 base-attack-missions per month, the doom clock should have finished the game, but this should be ensured in the actual code.*/
terrorbudgetadd = monthlyresources * terrorbudgetP;
monthlyresources = monthlyresources - terrorbudgetadd;
terrorbudget = terrorbudget + terrorbudgetadd;
/*terrorbudget is used to "purchase" terror missions. Given the units involved, these are extremely expensive, so it might take an additional month (and another failed base attack) to accrue the resources. They should on the other hand be designed to be borderline impossible to succeed on, and the player should be rewarded for merely *trying* to help (and loosing his units in the process). Personally i'd like the idea of spawning player controlled civilians on the other end of the map, and you get bonus points for every civilian that is with you when you evacuate from the mission (or who is still alive when you kill the last alien, which should be VERY unlikely). You can just sit on your spawn and move the civilians, but then the aliens on the map will almost certainly find the civilians and butcher them, costing you dearly in reputation in that region for every civilian killed. Or you go out and fight, but there's roughly 20 alien elite soldiers out there. Add in just a few reapers and let the fun commence.*/
baseattackadd = monthlyresources * baseattackbudgetP / 4;
monthlyresources = monthlyresources - baseattackadd;
baseattackbudget = baseattackbudget + baseattackadd;
/*baseattackbudget accumulates over turns until it reaches the necessary minimum value to "purchase" troops for a base attack mission. That minimum value rises by 25% with each failed base attack, but base attacks that did *some* damage through killing some personnel and destroying some facilities count as partial success, raising the minimum value only by 10%).*/
infantrybudgetadd = monthlyresources * infantrybudgetP / 4;
monthlyresources = monthlyresources - infantrybudgetadd;
infantrybudget = infantrybudget + infantrybudgetadd;
/*infantrybudget just continually grows, gradually reducing the percentage of non-combatant aliens and replacing them with ever better combat troops. Every ship (except those on terror missions and base attack missions) has a minimum required number of non-combatants which can never be replaced (for example 2 for a corvette) then there need to be at least 2 warriors for every officer, 2 officers for every elite and so on.*/
missionbudget = monthlyresources * 3/4;
/*Three fourths (or some other percentage) of the remaining resources go into "purchasing" missions / ships that will do missions. These are randomly selected from the available missions of scout missions, research missions, ground attack missions, air patrol missions, and base construction missions. Every ship has an "attack value" associated with it, which will, when multiplied with a factor dependent on the mission-type, determine how much money you loose if the mission is successful.*/
doomclock = doomclock + monthlyresources * 1/4;
/*This is the equivalent of the ticker in Xenonauts 1. The doomclock determines the size of the ships available, and will eventually just end the game. Not drawing resources by combatting alien forces will make the doom clock advance faster, and successful ground missions will increase next months budget for the aliens. Shooting down alien craft and killing them on the ground will lead to you facing tougher forces, and eventually make the aliens angry enough to look for you and kill you, or just murder random civilians if that fails. Note that if the doom clock advances far enough, the aliens will start sending down heavy assault craft or dreadnought bombers, basically resulting in the difficult but still doable terror missions from Xenonauts 1 - but these are still basically ground attack missions, just that the craft executing them have horrifyingly high attack values.*/
}//end of AlienStrategicAI
Of course i just came up with random guesstimations for the numbers here, and those would need to be refined for balancing, but i think it gives a solid impression of the concept i am trying to pitch.
3.) Improved Alien Tactical AI
Now this is maybe an unreasonable request, because writing a good tactical AI is a significant amount of work (and hence costs a significant amount of money). A reasonably simple suggestion i could offer, however, would be to give the aliens states of mind that determine their basic course of action for their next turn, enabling simple squad tactics. A possibility would be that an alien is either "hunting", "hiding" or "retreating". The mental state of each alien would be determined at the start of the AI turn for all aliens (else some will move away before the state is determined and the squad will break apart, retreating in different directions).
If there are 2 other aliens within 10 squares of this alien, or it has a clear shot at a target within 15 squares, it will advance in the direction of the closest threat to hunt it down.
If there is only one threat within 30 squares (40 are the range of a sniper rifle), and there is cover against the direction of the closest threat within 5 squares, the alien will move to that cover and hide.
If several threats are within 30 squares, or there is no cover within 10 squares, the alien will retreat, moving away from the closest threats and in the general direction of the UFO if possible.
This will generally make the scattered aliens group up, and then start acting in teams of 3. My personal experience in Xenonauts is that going alone is suicide, teams of 2 often just have bad luck and don't manage to kill a target in a single turn, and teams of 3 to 4 are usually enough to be effective but there's still enough cover to be found (if the odds are bad - say you are fighting androns with only base ballistic weapons and not very high accuracy, you'll need teams bigger than 3, but that is rather the exception).
Of course this wouldn't apply to the aliens guarding the UFO which default to "hiding" unless there is a target nearby.
(And just as a post note - yes, i am well aware they are no longer unidentified flying objects once we have a categorization of alien vehicles, but it's just way shorter than writing "alien craft" every single time.)
I hope any of this has been useful.
Best regards
~Drakon