[kbenson]

Here's one with 6: РڠໃמୡඤVŦலڄໃݲథɊІށ௨ಘQɕ௫ҨໃυɷඞМǶ௨ళɱݹ୦Οຯ൫௩ƦഫJமϺຽߢ௧uܘܭЬ௨൧ݹಈඤʆٻҳචHݹಏටฅکҿࡄแחजலາƷ௧οາঐ௧চІͷ௨ౚໃŧԥఠܕɕϢ෯ƚݢƐٮඍԣரಀԀສߜƣƬѣݫΝթֆଔ

I suspect that there's some pathological behavior in the game you can exploit to possibly get a line or more while giving up a line (not that I searched and identified one, I think I just got lucky on my second game because I don't play tetris much so didn't have much of a strategy to unlearn). It would be interesting if there a few of these behaviors that lead into each other, which could lead to a stable state of infinite lines.

Not being random means there might be more to exploit.

[salmonellaeater]

Yeah you can game it to fill in upper levels because it seems to greedily avoid letting you complete the next 1 row.

Here's a game with 7:

ԫقຽࡨதقลƻஸปໃɡЩටʈम౻ටիঅஶΟໃࡦѻ೯ܘݪ௨൜ІݚɪؾÐݪߜගІסञඉȣݣ౫ඞУݸԫؼПݒ౺sܪݚஶsԀŦਛfΔݹटɈເљࠑಜÐݶɺටळ൪ԪؾЂɚலڌෆࡨࢸదQॡభඝଘݒಈలНމࢲඖИܭޜϻϨॷభĐ

[b3orn]

8: ౚටරଳ௨ಗҾђञఢІŦଛقࠂɜ௨ఢVʣƃڠࠃʦذਓງஈ௧vഫݹযуಮɜटطϼƷ౻ඝЈஈ௩ΣܘŦ૧ට๒ݹଢඈฆŧذࡄɱݸϢరμŦௐؼVϳ௧৩ะݹ௨૫ຣ૨ரڴТߣ௧ڒІŒɷഗƖԤݛஶՀݮ൙൶ຯݷ౧Փຯబ௩ʡWђƓעXݪݖضɑЈԎϺثॿƖ੪СجƕןÞڍ۰Ռ

[kbenson]

A little searching and I found this: https://tetris.fandom.com/wiki/Hatetris#High_score which includes a replay for a high score of 31, which I've added below.

31: ௨ഖƌݯߜࠏІWƑsໃa௨೯ܘݷಳජଈیԪؼʥݺԥඞܘݲࠐڄໂঅமةໃݹ௧ړІٽ௨൞ໃZ௨ಘІܥࠐΣІZߜටȜখذජНݹߛeʛݹߤปເѧ௩ԚໂՉࢸටuа௨સȣݷłقෆঅਏeܘԔצقషݸɢڠຜঀಧҸມѧஐට༪൩ԊಅഫܡथsถԡԦԚໃɥஸقࡈɕɠɈไݸצقషݰਵϺФঅஓػݐɓԞуຯɕझࡈ๐ݞझࢶІݞमปദஈƉؿଭݪஸҩЂ൸ԛمϦGƁҨVھԥචЅշࡂ෮लݷƘණ໘ࠅƘಧНקࢻҨฆӘದԋϝପࠑ੧ͳݲடփරݞਵΚϼɢԒԺٳѦԤࠌξGಘسਯܥஶҋϮτथlϼʔ

[altvali]

small improvement to your solution, 9: సقໂɜ௨ഗƊݺɷටЖݹযמຽঅ௧ปໃঅਓsຯɜ௧ࡆଈŧԥටȤ൫௧ڈໃܘ௨කІԾ௨ඝІԘ௨ಳଈݰ௨൲ຣݹஜɦܗɚ௧ปลഴஐٯүݚ௩ظݕܥ౫ಀۻࡨஶԛɒঅਏڏІŧۑڐසђߥѲಊݷѻइࢳݪޜപࡊ०ணගɛܡ౦ಬҾɚ౫ఢʂډױ3

[barkingcat]

this one is pretty brilliant

[bmsleight_]

Another 6: ఢ૫ໃυޛඞਖࡨௐงເƍ౫൶ลٽ௨౾ІJ௮ටСݺԊق໐ɞ௨൜షݸ౻ටܬݹԪࡄถࡨ௭ඞФॡஸػʒஆಒ෩ಸݹࢳටଜݶౚ൜ਈމ௧෬ІھƐೲໄߢসࡆІݚɷ൜ປ൴ƋٯຯРமҔПܢமɈܢܭԤڌฅٽߤఏە

Agree it is like chess.