I have played it actually. Only getting 3 KOs may have been your downfall. You need to get more KOs to get more badges, which will then make your attacks stronger. Two of the KOs you got were early-game, meaning there was little chance of you stealing many badges either. I think 3rd place was just luck for you, possibly you were targeted very little, if at all, through the game.
🤷🏻♂️ What's that, 9 ko's? Let it be known I've been playing maybe 3 days now, so I need to practice my builds and all, but I think I'm a decently good tetris playing if anything I think i did the 150 lines mode in like 9-10 minutes
You need to practice working on back-to-back tetrises and T-spins. I think both cause more damage, but I've never actually been able to figure out the T-spins. YouTube might be your friend for that. 9-10 minutes is pretty respectable for 150 lines. I haven't played it much since they included single player, but my fastest is 8:50.
I got 7th but this was a better game, I got 11 line combo and 7 eliminations, half under 50 people left, and like 4 back to backs, I don't ever do need T-spins because I usually build on the left and leave a space for an I on the side, I need to work on my set up though.