I've played the PSP version of this a bit, enough to form a few brief impressions.

First off - there is a proper Monkey Ball in there in the form of challenge mode, which seems to be new levels but reminiscent of Monkey Ball 1. Not bad at all, but a little old. I've not got to the really tough levels yet, mind.

There are brand new mini games in there, as well as come classic ones, including Monkey Target. Target seems to be based squarely on the SMB2 model, but with more convoluted level design. That level design might break it, only extended multi playing would tell.

'Story Mode' seems pretty pointless. You begin on Jungle Island and are thrown straight into finding a castle, but are greeted by scores of NPC monkeys asking you for sub-Zelda sub-quests. The chunk of the game seems to be collecting bananas and completing errands (find this, collect that, stand over there) in order to increase the happyness rating of about 5 island 'hubs'. Progression is granted by completing puzzle levels to unlock doors.

Visually not bad, but the menus clunk along on the PSP in a slightly awkward 'THIS IS A PORT' sort of a way. They've come up with a new Monkey Ball lighting effect with is very nice, and despite the terrible cover art the Monkeys look as they did in 1 & 2. Character animation is changed though to better suit story mode, with your Monkey more convincingly in control of the ball, which is rather good too. There are also something like 20 new Monkey characters to unlock, which would probably be the main pull of story mode.

So um..., story mode might be worth persevering because of the unlockables, but doesn't seem that enticing so far.

Anyone seen the cover art by the way? Two things wrong:

1 - The Monkeys aren't in balls! Come on, thats rubbish!

2 - AiAi is smirking to his confident bad self... for a game where he grins all of the time, and only strives to makes monkeys happy. Dumb.