Thanks for checking it out! :)
Yeah, you're right, spawning the blocks with one size bigger would've made sense. As for tips, I don't really know how I could implement this... Especially after watching people play the game a lot of people came up with their own solutions that I didn't even think of when making the game, and I feel like adding a hint that for example shows the position of one block could kind of destroy that "creative" part of the game.