The game's unique art style, reminiscent of my own MS Paint days is a stronk choice. The core mechanic of managing resources, upgrading buildings, and defending against the monster is straightforward, as the monster grows larger and stronger, adds a sense of urgency and challenge.
The game really could still benefit from clearer labels and explanations for key elements like the monster's strength, building upgrades, and resource requirements. When the monster becomes too large, you cant see what is happening.
But once you figure out how to not die in first level, it is actually fun. Good job!