This review contains only my critique of the game; I won't reiterate the rules here, as is common on BGG.
I've been trying to think of a kind way to open this review, but I'm having difficulty. Most reviewers here would (and have) started by saying how Destination Portsmouth lacks any strategic elements and is, ultimately, a chance based race game. That alone should not make it a bad game though. I think it has several interesting and redeeming features, which could help to make this a very enjoyable game for kids, however, the terrible presentation and poorly written rules discount even that possibility.
I'll start with those redeeming features. The free-form movement which respects the 'drive on the left' rule and forces players to think about planning their route is quite clever (although immediately one of the several ambiguities in the game comes to light: Can you collect a fare whilst parked on the opposite side of the road?).
The business model is interesting: Target the game at a specific location (i.e. Portsmouth) and entice local businesses to invest in the product's development in return for prominence on the board. I imagine this could eat into the game's profit margins as more and more retailers request broader coverage and inevitably there will be locations which never get their own version.
I also quite like the basic fare collection mechanic, combined with the need to buy petrol (although the rule for running out of petrol is ludicrous: Perhaps another player will sell you some? Although if they won't you're out of the game!). The problem is, to counteract the money you earn from fares, you lose money via a selection of random 'chance' cards. It seems it would have been much more relevant to tie expense to distance as is really the case. Perhaps players could opt to avoid unprofitable fares, costing them in time but not losing them money?
In fact this is the main area of the game that would need to be altered to add the much needed strategy. I think it would possible to create a very interesting game out of the basic Destination concept. First, change the construction of the Destination cards. Each would actually be created as a combination of Pickup and Destination (i.e. A punter at the Shopping Centre wants to go to the Train Station). There could be three or four of these active at any one time (depending on the number of players, and perhaps an element of chance) and they would be available to all players. The players would need to work out how much profit there is in the ride and offset this against how much it would cost them in petrol to get there. On top of this there is the risk of another player getting to the Pickup before them. (It's a shame, because I'm fairly sure Rachel Lowe, the designer of this game, realised this should be an element of the game because a very contrived rule has been included which effectively results in random taxi teleportation.)
The dice based movement would need to change. Players would instead have control over how fast they were travelling, but would need to respect the rules of the road, watch out for speed cameras and avoid getting stuck behind other players without being able to overtake.
But of course I'm rambling, like I always do. And this is all fairly irrelevant because I think this game would always be more appealing to younger players. A little simplification in game play and lot of clarifications in the (hopefully completely re-drafted) rules would go some way to making this game more suitable for youngsters. More important though would be a rethink of the presentation.
There's no excuse for not making things clearer on the board. Each Destination should be boldly represented with an iconic graphic - which are mirrored on the Destination cards themselves. The city should be sectioned (they often are in real life) with the different areas (or quarters, even) colour coded to aid quick identification of the important targets. But instead everything looks like it's come out of Microsoft Word. Copious use of bland serif fonts and a distinct lack of imagery make it very hard to find anything or get familiar with the board. The roads should be littered with arrows so it's clear which way you can turn (or should be travelling). The traffic light cards are split into two even groups Nice and Nasty and yet they all comprise some black Times New Roman on a white background.
Yes the box art is nice (as is the background image on the board, which alas is practically pointless) but the important parts of the game's presentation, that of all the relevant information, is bland and lifeless.
In summary, Destination Portsmouth could have been so much more but ultimately bad design (of the rules and the graphics) means it fails to succeed for either end of it's broad target audience.