Sorry OP, its just when you start comparing this game to other games, people are obviosly going to jump in and voice their own opinions and/or 'correct' your opinions. lol
As far as MtG, ITS defining characteristics are
1.) Monsters and how they interact with things (W;I has no direct blocking, no summoning sickness, persistent damage, resource system built in to the units, etc...)
2.) Mana system and its acquisition (W;I has very little mana screw which I find pandemic of 50% of all MtG games I've played)
3.) Color wheel (W;I has a similar one, though it's loyalty system is SUBSTANtially different than MtGs).
4.) Rarity (W;I LCG = instant difference)
5.) Planeswalkers, and generic anything goes fantasy / sci-fi setting.
What other games have you played, TCG wise lately? I'm sure I could compare those to MtG and just call them MtG inspired as well, if you'd like.
Like perhaps Netrunner, which has money (mana) programs (creatures) and a victory condition which is contingent on defending something / acquiring things that the opponent can interact with through their programs (creatures) which is essentially a strict counting up system.
Also... I've also found that 'expecting' things from a TCG is the best route to take to be disappointed. Heh.
Game on. (PS after enough time with games, every game seems like a copy of another... I've gone through WAY too many TCGs... they all kinda blend together after a while...).
Netrunner has a great number of differences over M:tG that make it a radical different experience. For one thing, the core mechanic of both players having to chip each at HP of the other player simply does not exist. The corp has to build his resources...the netrunner has to make attacks on the corp player and both prevent him from getting too much power and by exposing his resources. There is a fundemental difference in gameplay where one player does not need to even interact with their opponent much and the onus is on the decker to cause the oppositionn. Money is persistant, which it isn't in both M:tG and Invasion. Programs, while have a likeness to creatures, have a type, if you recall. Where one program (creature) cannot deal with all types of IC, unless M:tG or Invasion (M:tG does have flying creatures but the point is not the same, as flying just prevents the creatures from fighting, it does not prevent the creatures from interacting differently). The Decker needs to probe the defenses of the Corp to see where the corp is weak, as ICE has many forms (Datawalls, Codegates, Black IC, etc). The decker also had the option to fuel his attacks, which is not a feature in either game. Netrunner did not have the attack/defense concept either. The decker had to have a separate program to protect him from damage deal to him in the Net.
So with that in mind, I disagree with some of the assessments made.
1) Monsters do all possess an attack and defense. Monsters have to be sent to attack the enemy and may be blocked as needed. The combat system is slightly different but they function remarkably similar. Unlike M:tG damage is tallied up and assigned. Had they allowed for a randomizer, as Sabertooth games did in their 40K CCG (albiet not all units had a randomizer), that would have been enough for me to view them distinctive enough from each.
2) Hmmm, I still see it as functionally the same. In both games, you had to lay down cards to get resources. Invasion does have a better core concept, in which you always get 3 resources (which you don't have to do anything to earn) but you will quickly find that you need to put down some cards in the Kingdom zone to get more out of it. I will give you that it's unique in that the cards that give you resources can also defend. That's a nice concept. But you spend them very much the same.
2.1) Going back to Netrunner, their resources were presistant and the method in which you spent them was rather tactical/meaningful. The decker could use resources to 'fuel' their attacks. The corp could play IC facedown for free and then 'rez' them at a moments notice OR they could just rez them when they were played. That in and of itself was an interesting concept of how resources interact with your game.
2.2) Going back to my preconcieved notion about this game, when I heard the concept of developments, where you play a card face down, I thought that was going to mean that you could build a card over time. Like building up a structure rather than paying resources for a village. I thought that would be really neat, but alas, developments are really just a word that they choose. They could have used the term: Speed bump for all it mattered. They do do more in the game than would first appear (many cards gain bonuses based on you having developments in the zone) but they are quite lacking in flavor.
3) You're correct. The colour wheel is very different. I like what Invasion has done with their loyalty, however, it's largely moot if you're not using alliances. You'll be swimming in the loyalty very quickly.
4) Yes, rarities are different. I clearly can't argue that.
5) Well, that's a setting specific comment...so...I can't really touch that.