Multiplayer game winner will lose if all other players leave the game or press Play Again before they finish

[ltfschoen]

If you play two player on mobile, and if player 1 hits the first obstacle but the other player 2 doesn't hit the first obstacle, then player 1 result will be "waiting for other results", and on player 2's screen it will still show player 1 in the opponent list shown in blue, but if player 1 leaves the game (closes the browser tab, or even presses "Play Again") then they won't appear on the opponent list for player 2 anymore, and if that happens before player 2 hits a subsequent obstacle, then player 2 will lose because the game isn't correctly keeping the context of all the players that actually started anymore.

so need a fix where even if player 1 leaves the game before player 2 also hits a subsequent obstacle, player 2 will win...
and we need to communicate what's going on to the players

but also don't want a situation where someone with multiple browser devices and multiple browser tabs open tries to play them all at the same time... possible but hard.... and since some openings are at the bottom of the screen they might clear some obstacles not even pressing anything and possibly win... and don't want them spamming games

so we need the following changes:

• first obstacle must prevent players clearing it if they don't press anything (i.e. the gap can't extend all the way to the bottom)
• only allow a winning result if at least two players joined the game at a starting block (that's already the case) and if at least two players clear the a high number like the x-th block (proof of actually playing lol), to make it harder to win, and to have less asking for tips, and to make it harder to predict the result on prediction markets
  • note: we don't penalise them for not clearing the first block because players also need to learn to play, and we don't want to discourage them by throttling how often they can play just because they're learning keep hitting the first block (not spam)
• add a "Practice" button instead of just "Play" so players can just learn to clear blocks, and allow them to play immediately single player (also for those who are addicted to the game and too impatient to wait for other players to play a game)
• penalise players that click "Play" (instead of practicing by clicking "Practice" enough) but that don't clear at least the first block by making them wait say 30 blocks until they can play again (how long measured in blocks is the average game length? if it's 10 then they miss about 3 games). this is to prevent players spamming to win. this could just be stored on the backend, but could also be stored in a smart contract as a form of game player credibility..