I'm writing this review of "Colosseum" as a comparison between it and "The Princes of Florence" (hereafter abbreviated "Princes") primarily because the game play in Colosseum almost demands the comparison. Usually people use the term "stark" in conjunction with a reference to differences as in the phrase "stark contrast". With Colosseum, I would say that there are "stark similarities" between it and "Princes". However, I find in comparing the two games, that "Princes" is a hands down winner on pretty much every level except for the beauty of the artwork (and even then I have some issues with how Colosseum is laid out). Perhaps the easiest way to summarize the comparison is to say that Colosseum is like "Princes" but with baggage. So, let's look at why this is.
Both games last for a set number of rounds (Colosseum: 5, "Princes": 7)
Both games have competitive auctioning as well as purchasing possibilities from a limited market.
Both games have a number of point scoring goals you work towards that are each unique in the things required to score the maximum points possible (Colosseum has attractions/programs - each requiring a unique tile set of different performers to achieve maximum points while "Princes" has Works with a unique requirement set for landscapes and buildings) - this is the strongest similarity between the two games.
You can play an attraction in Colosseum or a work in "Princes" without having all of the required items but you score less points for it.
If you have the best attraction / work of everyone in a round, you get three points for it (in Colosseum, those points count towards latter attractions and represent a recurring form of point scoring. With Princes, the three points are added immediately and are not recurring.)
You can acquire items that can, for one time only, increase the total value of your attraction or your work (for Colosseum it's Medals while, for Princes, it's Bonus Cards).
You have to make choices as to which actions are the most important to you as you only have a small number of opportunities to purchase things.
Because of these similarities, it comes as no surprise that the same designer, namely Wolfgang Kramer, was a co-designer for both games. Granted there are differences. Specifically, there is the Emperor as well as various Senators in Colosseum that may or may not attend your attractions depending on luck (you roll dice). With "Princes", the luck in the game is mitigated by drawing 5 cards and then picking the one out that you want.
The Auctioning System
The auctioning system is more complicated and less satisfying in Colosseum than it is in "Princes" for several reasons. First, you are not bidding on a single item or tile. Instead, you are bidding on sets of tiles (three tiles per set). This might seem like an improvement over "Princes" as much of the tension in the game "RA" comes from having to decide how worth it it is to you to bid on something with a mixed set of variables. However, the fact that tiles can replenish after a bid is taken makes the auctioning less interesting and more random. Further, the tiles only replenish and other players cannot bid again after they have won a bid until the initial bidding player finally takes a bid. Also, the auctioning can continue in Colosseum such that a person could win two or more auctions in a given round.
The auctioning system in "Princes" is less complicated and more tense because people are fighting over more similar things and, once they have won a bid, they are out of the bidding. This means that the decision to raise a bid and potentially take it carries a lot more weight in "Princes". In Colosseum, it's too easy (even with 5 players) for everyone to be going after different things (which dramatically reduces the tension involved in the auction).
Attractions vs. Works
With Colosseum, you can only play one attraction per turn. You may, however, play that same attraction over and over again over several turns if you choose to - which lessens the tension of playing it. With Princes, your actions are limited as well but you can play multiple works in a given turn. However, once you've played your work, you can't play it again unless someone recruits it from you and you then recruit it back. Thus, you have to decide if you want to play your work early and take less points for it or play it later and get more points for it - a decision with decidely more tension involved than what Colosseum offers.
The one main criticism of "Princes" is that the player interactivity is low. Colosseum does have more player interactivity. You can make trades and exchanges with other players involving tiles and money. There is also some indirect interactivity in that how the players move the senators and the emperor on their turn can impact the other players' abilities to score more points on their respective turns. However, the movement of the senators is not that interesting of a decision making process.
The main source of interaction in Princes is the auction and the limited market (not having enough of everything for every player to acquire one). So, what other players do on their turns with respect to purchasing items in "Princes" is more interesting than what other players are doing on their turns in Colosseum. Because everyone's tiles are out in the open in Colosseum, you can reasonably deduce what attractions they are most likely gunning for. With "Princes", by having less variables, there is actually more intrigue because you honestly can't always figure out exactly what the other players will be buying next. There are simply more possibilities that might be reasonable for them as the smaller number of variables at play have a wider range of possible solutions. Also, the works that other players have in their hands is secret and each player's money supply can be kept secret - both of which are aspects that add more intrigue to the game when compared to the open resources of Colosseum.
Ok, the artwork on Colosseum is typical Days of Wonder: very colorful and attractive. However, the functionality could have been slightly improved. The auctioning mechanism of how turn order flows and who can bid and who can't is quite clunky in my opinion. Some additional components could have easily helped make this mechanic a lot smoother by helping the players to keep track of things. Also, there are various tiles that award bonuses if you have the most of them but not all of the tiles are eligible for this bonus. Just like how RA incorporates the use of a symbol to remind the players of which tiles stay and which tiles are discarded at the end of a round, it's my position that Days of Wonder could have included symbols on the tiles to indicate which ones are eligible for a majority bonus and which ones aren't. This small addition won't make much of a difference to experienced players but it would help out a lot in trying to teach new people how to play the game.
The bottom line here is that, in my opinion, if you are looking for the kinds of decisions and intrigue offered by Colosseum, then "The Princes of Florence" offers many of the same kinds of decisions but does so to a greater, more fulfilling degree and in a more streamlined, less complicated fashion. Colosseum has more pieces involved in it's structure, but "The Princes of Florence" has stronger depth. Perhaps the easiest way to say it is that, sometimes in life, "less is more".