The variety in the game is over pretty fast. The graphics are nice and the voice over was really fun!

I like the gameplay idea of defending an object but wish I had a little more to do. Perhaps give the player the ability to spawn the lava spots with a cooldown and limit the player's needle fire weapon a bit to add more strategy. The way I completed it was just holding the fire button and aiming at the four corners of the screen without waiting for the zombies to spawn.

Nice work!

Great Game and Great job! here is my feedback:
-I really loved the starting screen not many devs does this so great job ! but i noticed a weird bug, where if i played the game in the web, changed the tabs the audio would still be playing and even after the audio finishing and returning back to the tab the player would have to wait for a long period of time.I am assuming you have some delay/timer that is X seconds long the same as the audio file, i don't have experience with Gdevelop so i am not sure if there are signals to check when the audio finished to change the scene like godot, but try to look into it.
-Really Great job on the SFX, but i also would recommend adding music
-I noticed that even when the heart counter reached 0 (3 gray hearts) the player doesn't lose, only a damage after this cause death (not sure if this is intended but it felt a bit odd)
-I also recommend adding a lose menu to restart the game instead of having to restart the website to play
Overall, it is a fun game to play so great job !! and keep it up!