Unfortunately, i don't really have time to be much of a gamer. The personal time that I get tends to be spent on photography or messing about with music related things. That being said, I do enjoy playing computer games and so do my two sons. We pretty much entirely play them on iPads (except for Civ 5, for which you need a proper computer).
When my sons ask me for a new game, or when I am considering one myself, I tend to find myself taking a dim view of any game that is free to download and install. This is because the vast majority of free games are, in fact, not free. Players either have to pay money in order to render the later parts of the game playable, or they have to pay attention to advertisements. Often, these factors wreck the user experience of the game (and it's not unknown for the advertisements displayed to be inappropriate for the age rating of the game).
When I pay for a game, then there's a clear up-front view on my part about the cost of playing that game. However, when I install a "free" game, the cost is much less clear, because I don't really know what in-app purchases will be required. Worst of all, getting me to pay now becomes part of the gameplay rather than being confined to the initial transaction.
Instead of having a single objective of being fun to play, free games almost always have this second undeclared objective of getting money out of the player. The second objective is critically important to the game publisher, and will usually exert a corrupting influence on the game design and gameplay. For example, initial progress in a game may be rapid and enjoyable, but once the player is invested in it, the game ramps up in difficulty to an unplayable level. When the player is consequently stuck, the game will make it easy for him or her to spend their hard earned cash to buy the "lives" or "lollipop hammers" or "rings" (or whatever) to provide a much needed shortcut out of the in-game difficulty. When they get stuck again later, why look! They can buy more!
I see this as yet another example of a way that the psychology of addiction is employed to get money out of people. It feels sneaky to me, bordering on dishonest, and the more dramatic results can be seen in the stories of people spending hundreds, or even thousands, of pounds to play an ostensibly free game. I expect that most of the people who have spent more than about £15 on playing a game in this category would not have installed it in the first place if the cost of playing had been clear up front.
This somewhat shady picture, combined with the accompanying lack of clarity about the costs are why I won't install free games, and I hope that when my sons are old enough to understand this, they will forgive me for my apparently complete unreasonableness on the subject.
The exception that proves the rule...
There is an exception to my dislike of in-app purchases for games. This is where a one time payment is required to unlock the full version of a game. I see that as an entirely legitimate and above board mechanism to allow game publishers to give away a free trial of a game.