Good on principle, Nikita, I fully support this, but there's a danger - if you overdo it, you get Homeworld where player is forced to meta-game and play badly on purpose, because stellar play leads to the game getting unwinnable. There has to be a very solid logic in place for every change in enemy/x-com behaviour, and it has to go both ways - if you're performing very well, not only aliens mobilize more of their resources to kill you, but also x-com agents are getting complacent and less focused, being drunk with victory. Also, both sides need to have a counter-action possible - when aliens mobilize, you can shift from confronting them head-on to harassing warfare, striking their supply lines, while strenghtening your defences; when x-com agents are getting complacent, you intensify the discipline (court-martialling troublemakers, for example, which means loss of veterans). Such mechanics would ensure that a player won't have to metagame and play badly on purpose - he'd just have to shift in-game strategy, action and reaction, diminishing returns. Conversely, a player who plays badly or is unlucky won't be given any gifts, only opportunities (but a bad player won't be able to take advantage of these opportunities).