A Tower Defense Game, Literally

This is a generic tower-defense game, but instead of being top-down, it focuses more on side-scrolling part.

Story: Its year 2756. Humanity was on the verge of finding the cure for death, an antidote that would make any human immortal, but the mishandling of this antidote made it into a virus that would make its host an undead creature hungry for flesh. In only 50 years the virus has spread so fast that only a handful of people were still alive. Those remaining few have gathered into this place, a tower in the middle of the desert, and cast themselves into a cryogen casket that is supposed to keep them frozen for a period of time, hoping that the virus will go away on its own. But it seems that the zombies have found them. However, this tower has some pretty good defense mechanisms that they need to get through first.

Controls:

Mouse - for mostly everything

P - for pause

'A' & 'D' / Arrow Keys - for navigating left & right

1, 2, 3, 4, 5, 6, 7, 8, 9, 0 - for selecting the tower level

Music:

Brandon Morris - Loading Screen Loop (https://opengameart.org/content/loading-screen-loop)

ERH - BlueBeat 01 [loop] (Cyberpunk Lab Music) (https://opengameart.org/content/bluebeat-01-loop-cyberpunk-lab-music)

Fato_Shadow - Military (https://opengameart.org/content/military-soundtrack)