Power Dunks
When in the main menu screen, type "redrover" in all lower-case. At
this time you should hear a noise.
Michael Jordan
Defeat Michael Jordan one on one in superstar mode to unlock him on
the roster.
Isaiah Thomas
Get fifteen steals in a game in superstar mode to unlock him on
the roster.
Michael Jordan, The Easy Way
Pick a player in superstar mode against Jordan. Set the game
match to 11pts. At the controller setup screen, select Jordan as your
player. Let the other player score 10 points against you, then switch
the control back from Jordan to the other player. Now all you have to do
is score 1 point on Jordan.
All-Decade Team Players
There is a set of five All-Decade Teams (1950's through 1990's), and
all of the players on those teams can be unlocked to become available
to put on any desired roster. In order to achieve that for each player,
the game will give you hints as to how this may be done. Michael
Jordan, for instance (as well as for Wilt Chamberlain and one other
player from the 1950's team), can be unlocked by beating Michael Jordan
with any player in the superstar level in the game's one-on-one mode.
If there is a way to u nlock players by achieving certain performances
in a single game, the easiest way to do that is to use a great team
(like the All-Decade Teams) against a poor one (like the Chicago Bulls).
For seasonal achievements, just work your way through it. All the
achievements can be achieved, but if you want to win by a lot over a team,
do not try to make 15 'threes' or pick up 30 assists in a game -- just
play up-tempo basketball. If you try to make the achievements, watch
yourself because you also have to win the game to unlock the legends.