Thanks for your feedback! :)
We’ve been trying to balance the game, and if Pingus fell automatically, we think the game would be too frustrating. Adding more Pingus makes it harder, but it adds more points per second, and the total Pingus alive at the end also adds a lot of points. I understand that you want to get to the end with the minimum number of fallen Pingus, but it’s actually not the best strategy in terms of points! :p
For the replacement, we had the idea but abandoned it because we didn’t think it was necessary, but maybe it is :/.
For spawning, we thought it was a sweet spot, but in fact the RNG can make situations without blocks for too long :/