Excellent game
I found this game to be a superb example of the 'base defence' genre. The steampunk atmosphere was nice, but not as convincing as it could have been. It could have been that the gameplay was too reminiscent of 'Nazi Zombies,' or that the graphics didn't really allow one to see the protagonist's ingenious Victorian-era constructions clearly. The turrets did not seem particularly helpful, either.
Other than that, the other thing I did not like was the difficulty, which is not particularly well-scaled. Only the 'Mad Bomber' alien was a real threat to the player, as it seems to be an instant-kill if it hits you. The other enemies, although interesting and varied, were not particularly dangerous, even if they entered the base. For example, the 'Juggernaut' was so slow and harmless that I could ignore one inside the base whilst I repaired the other three barricades.
The uneven balancing of the enemies (with only the 'Mad Bomber' and perhaps the 'Charger' posing any real peril) may also be because the player can repair barricades whilst shooting and reloading, and doesn't need to be even facing the barricade.
I would suggest either modifying or nerfing the Mad Bomber's damage (perhaps have it do half the amount of damage, but immobilise or stun the player), and perhaps make barricade repair a separate task, i.e. that one must be immobile, facing the barricade, and not firing. Finally, perhaps a level-based design would be great, as it gives the player a goal to work toward, other than earning a high score no one will care to see, or resisting an infinite number of waves in an ultimately futile defence.
Overall, a splendid game. Thank you for listening to reviewers of the prior version and removing the Mochi coins. I hope to see a sequel improving upon this.