Roma is a light, two-player-only strategy game, thematically set in Ancient Rome. The connection between theme and play isn't strong, so I'm not exactly sure what the gameplay is supposed to represent; the object of the game revolves around scoring Victory Points, after all.
The mechanics of the game combine to create a nice mix of luck and strategy. You have six card slots on your side of the board (numbered 1-6), and each slot can only hold one card. On your turn you roll three dice, and generally you use a die to activate the special ability of the card in the appropriately-numbered slot. Instead of activating an existing card, you can also use a die to draw cards (draw a number of cards from the common deck equal to the value showing on the die, keep one and discard the rest) or gain money equal to the value showing on the die (which you use to pay for playing cards). So effectively, you have three choices on how to use each die: draw cards, get money, or use a special ability.
This alone creates a difference in the numbered card slots. Rolling 1 or 2 on a die isn't particularly useful for drawing cards or getting money, so you want to have your more powerful abilities on the lower numbers. Your opponent knows this, of course, and will either do the same or will do their best to counter you.
The card abilities themselves are a varied bunch. You have cards that remove your opponents' cards from play (usually only the card in the same slot, and usually only on a successful die-roll). You have cards that let you draw a card of your choice from the deck or discard pile. You have cards that mimic or stack with the abilities of other cards. And, of course, you have cards that score Victory Points. Ah, Victory Points.
The objective of the game is this tug-of-war for VP. You each start with 10 VP, and there's an additional pile of VP in the center of the table that's unowned. Various cards let you either take VP from the center pile or from your opponent, and you pay VP back to the center each turn for every card slot you have that isn't occupied by a card. The game either ends when the center pile is empty, or when one player runs out of VP; whoever has the most, wins. This leads to a changing dynamic in the game. Early on, you're both leaking VP like a sieve, and it's tempting to go for the early victory by running your opponent down to zero before you fall too far yourself. Mid-game, both players tend to have their VP engines up and running... but one player is a little bit ahead so they're trying desperately to end the game by emptying the center pile, while their opponent is trying to steal VP from them to chip away at their lead. If one player gets a good combo going, the other player will either try to destroy the cards, or frantically burn through the deck to get the card they need to destroy it. For only three dice with only three possible actions each, the game has surprising depth and interesting choices during play.
This strength is also the game's weakness. Every card has at least three or four ways to undo or counter its effects, but the players are expected to know what those are. The strategy really only begins to take hold, then, when both players have memorized the entire card list and are fully aware of all of their many options. In other words, the game has a pretty steep learning curve, far more than one would expect from the otherwise simple rules. (It doesn't exactly help that, in an effort to be multilingual, cards have no ability text on them but only icons, so you basically have to have a complete card list available as you're learning. Nor does it help that the rules are vague in some key places, so you pretty much have to not just read the printed rules but also hunt around the internet for additional resources. If Stefan Feld designed a game and hired Matt Leacock to do the user interface, I'd be a very happy gamer.)
As such, this game will not appeal to everyone, but only those willing to put in a fair amount of time and practice. If you do, you are rewarded with a non-collectible, non-tradeable game that nonetheless has a distinctly CCG-like feel to it (due to the variety of cards and special abilities, and the draw cards / pay resources / play cards mechanics).