Games with Stealth Mode enabled will have hidden score information. Only the Planet count of your opponents will be visible as a way to gauge their strength. No more looking at ship counts, military score, starbase count or even knowing when the ship limit will be hit. In addition, when a Badge is awarded, it won't be announced in the game's Activity feed.
These games are for advanced commanders looking for an exciting and intriguing diplomatic scenario!
NOTE: With the exception of player name, number, race, and planet count, all Scoreboard data in a Stealth game is invisible, even your own. This can be problematic; the only possible way to view your total accumulated Priority Points, for example, is in the starbase build screen.