I think it was either level 4 or 5.
Also some other things I forgot to mention is that cherry bomb, potato mine, and pineapple bomb could use a buff like a bigger explosion size. Everytime I try to use a insta plant it sometimes doesn't hit certain things even though it was in the explosion range. Ex potato mine detonates from a fast enemy after the bloons break through a wallnut but the other slower enemies dont die behind it.
It would be nice to have some more options in the pvp mode since 3 plants and bloons only feels restricting and hard to try out different strategy's. Level 2 is just way to hard with the first enemy being the newspaper zombie, the amount of gaves and rng for graves, and the first wave having a bunch of coneheads and lead bloons is to much to handle.
Also id be nice to see what enemies would spawn in a level to.
These are things I discovered after playing more