I bought Duke Nukem Manhattan project back when it released at a budget price. Thought they'd just cut back the scope of forever and thus the price to actually get the game released on time.
On playing it, I found it was in fact nowhere near the game Duke Forever was going to be, but a rather enjoyable 2.5D platformer.
Then eventually Gearbox released Duke Forever, which really wasn't all that bad. My main problem with it was Duke seemed to be suffering an identity crisis. Gone were the open exploration levels and huge arsenal in your pockets (or where Duke carried his arsenal) in favour of the more linear and limited arsenal in vogue at the time. If they had made the levels a bit more open and let you carry every weapon at the same time it'd have been a rather good game really (in my opinion)
As it is, Manhattan project proved the more entertaining of the games. And even seemed to be more open to exploration than Forever, which is sad considering it had half a dimension less.
Matewis: Guess should grab Duke 1 and 2 then :P How are they, really? Is the level design comparable to the brilliance of Commander Keen and Bio Menace?
Duke 1 had levels somewhat like the first three Keen games, but they always more evoked the feeling of Secret Agent for me.
Duke 2...I never completed the thing, the too close camera just put me off wanting to play it anymore.