First of all, we would like to thank you for giving your kind feedback on our little game we made in this 3-day game jam. We are glad to know that you played and liked our game.
The reason the platformer levels feel a bit unforgiving is because when we were playtesting the levels, the level duration itself felt very short (you could easily complete a level under a minute if played perfectly). So due to lack of time, we decided to make the level a bit challenging so that the player cannot rush through it. We wanted to increase the time spent playing since the game itself is very short. That's also the reason the spikes on the ceiling are insta-kill.
The spaceship defense part works a bit randomly, sometimes it spawns more fast moving enemies and sometimes it doesn't at all. We had tried testing it with more enemies, but it was causing issues with the level sound (the bgm was being washed out by the sound of shooting bullets by the enemies). We balanced it out by reducing the no. of enemies spawned at a time. So that maybe the reason it feels a bit too easy?
We admit that the game has a lot of scope for improvements, and we will surely improve upon the flaws pointed out by you. It's an honour to have our game reviewed by the game engine's developer himself!
Thank you so much for organising this amazing event! :)