Start at the top of the board. Die has 1-3 Red; 1-3 Blue. Roll die and move the indicated number of spaces toward the red or blue side of the board (southeast and southwest). When you reach the bottom, move up, again going east or west as indicated, but no movement if you would be required to move off the board (which can happen about 1/3 of rolls when moving up the board -- a real problem with the game).
If you land in an open hex, buy any unowned property from the bank and place its marker in the hex. Alternatively, move any of your existing properties to the empty hex in which you landed.
If you land on another player's property, pay rent. If it is a tryopoly (the entire set is on one row), pay a lot more rent.
Note that many sets are too large to fit in a row near the top of the board. Also, the spaces near the top of the board get hit more (because there are less of them, and movement near the top is much more constrained). So there's a definite tactic of creating your tryopolies as far up (north) on the board as possible. There's a defensive tactic of leaving a property in a key location to block someone else from making a tryopoly.
However, there are also special tiles, which can also be moved like the properties. Landing on these by exact roll allows actions like swapping tiles (even if owned by other players, unless the property is in a tryopoly), gaining money, paying penalties, buying property from other players at double cost (again, only if it's not in a tryopoly) etc.
The tile at the very top of the board can't be moved, and serves as "go" with players getting income when landing on it (which by necessity must happen when you move up/north on the board).
Players are eliminated when they are unable to pay rent or fines. Winner is the last player left solvent.
Note that these rules are from my memories of playing the game 20+ years ago, and may not be correct in all aspects.
Good memory, and I'm glad there's at least someone else that's played this! (I want to get one more game in before rating it, since I've only ever played a 2-player game.) There's only one rule that needs clarified: a player can purchase or move a hex for every open space that player passes over, in addition to the one (s)he lands on. And just to be safe, it's good to know that you can always sell your properties to the bank (never to another player) for half the purchase price.
And you're absolutely right about the pain of moving back up the board. I suppose you could think of it as being in a rent-free Jail, like in Monopoly, but even then, this part of the rules feels more accidental than purposeful. Maybe a house rule is in order: if you can't move, you may pay $5K (the smallest denomination) to the bank and roll again.
Some other fun -- useless -- tidbits, from the rules:
* 2 players start with $1.5M each, 3 players $1.25M, 4 players $1M, 5 or 6 players $750K.
* There are 10 special spaces, most of which a player may move in addition to any of their owned properties:
1. Start (just as you described, no reward given -- also cannot be moved)
2. Collect $50,000, which is first placed in the row underneath Start
3. Collect $75,000, which starts beside $50,000
4. Relocate 2 Properties (includes special spaces -- either move them to open spaces or swap positions with each other)
5. Buy One Property for Double (since trading is forbidden, this is the only way to obtain someone else's property, unless that property is part of a tryopoly)
6. Lose One Property
7. Collect $100,000 from Each Player
8. Pay $250,000 to Each Player
9. & 10. Red Corner Card & Blue Corner Card, which not only guide the players' movements, but when landed on allow a player to either relocate any opponent's property (even if part of a tryopoly) or move to any special space.