I don't think any of the Connection/Connexion versions were that similar. Here's a list of all the versions, with all of the new things between that version and the previous version that I can think of (this is Connection/Connexion-wise obviously so please don't say something like, "Gotchi Points weren't new in the v2, they were out in the Keitama!).
The v1 was simple, raise your little pet and then connect it with other Tamagotchi to develop relationships and perhaps mate.
The v2 was like the v1 with a lot of stuff added on- shops (as far as I know this is the first version worldwide to have a proper shop, instead of a street vendor), items, Gotchi Points, treat option in the food menu (this is where ALL the foods you bought in the shop went), shop codes, food likes/dislikes (I think they're on this version anyway), the ability to choose game or present when you connect, the ability to wrap or delete items, different games and where I live, the v2's pause function was new and some of the words in the check meter and other places had changed.
I think the v3 was quite a bit like the v2. I don't know what makes me think that though because there is still quite a bit of difference. First of all, entering Tamatown with the unique username you set yourself at the start up, then entering passwords back in your v3. Also there were more games, more money you could win from the games if I remember correctly, souvenirs that were obtainable from Tamatown (but could not be used), the ability to donate Gotchi Points to the Gotchi King to get souvenirs, a special item and more money from connection games, the ability to choose exactly which mean and exactly which snack to feed your Tamagotchi, some new items that were not on the v2, the ability to choose game, present or visit while connecting, the option to view family history and the departed Tamagotchi and the ability to win Gotchi Points from connection games. Also there is the antenna which I find quite annoying.
The v4 in my opinion was quite a bit irritating. Anyway here are the new features in v4: your character can earn skill points which influence growth, you need to enter in a username AND password combination when entering Tamatown, when you went to Tamatown you could win up to 9 900G and up to 10 items at a time before getting a logout password, you could receive mail (fortune cookie, normal mail and important mail), an even more irritating antenna (worst of the lot in my opinion), the ability to enter preschool, school and work, the ability to view a little animation when you pressed C, the fact that you do not have to turn out the lights when your Tamagotchi sleeps (it turns them out itself), secret characters obtained by high skill points, the ability to earn up to 99 999p (instead of just 9 999p on v2 and v3), different games and different items.
The v4.5 was a tiny step up from the v4. In fact I don't think it was a step up at all. The only differences worthy of noting (in my opinion) between the v4 are: it has different characters (but there is the same amount of characters), it has different kinds of skill points (but there is the same amount of kinds of skill points), it has different jobs (but there are the same amount of jobs if I remember correctly) and there are different games (but there are the same amount of games). Oh yes, the antenna is slightly different too. Instead of a sphere at the end of the antenna there is a star instead.
The v5 was very different to the v4 and v4.5. For the first time in about four years, they've finally managed to get this version very similar to the Japanese version! (The last time they've managed to do that, that was in about 2004 with the v1.) You can raise more than one character at a time. On your second generation or higher parent characters appear throughout the day to do special animations, and parents also help their children with the housework (and raiding the refrigerator!) as well. You can also see the parent characters during medicine time, when eating or when playing the Golf Putt and Shoe Pairs games (they are only unlocked from second generation or higher). Instead of the standard discipline they have a different form of training which involves giving the family members items to play with. One thing about this version is that you aren't forced to name them which is a good thing for two reasons: a) you don't have to name them if you don't want to and
if you want to name them you have no limitations as to how long the name can be. I could go on but I don't particularly want to.
I'm sure you're not the only one who feels this way.
