In Steam Power, players "race" to build the best rail network to meet their contractual obligations and make the most money.
On your turn, you can perform two actions from a selection of choices, letting you lay tracks, build factories, fulfill contracts, earn money, or collect more contracts. Building a factory brings resources to the board that all players have access to...at a price.
The game ends when a certain number of contracts are fulfilled, which varies by player count. The player with the most points (and money, which converts to points) wins.