lot`s of work needs here.
some advices and bugs:
1) add wasd/arrows control - mouse cotnrol are very hard on the bottom
2) skulls must NOT drop from screen, always inside. make them bounce of borders
3) graves must be 2 shots. or increase chanses of skull drop in 2 times
4) add some constant upgrades, such as power or firerate
5) plants and stones must be indestructable or must not stp bullets - 1 from 2
this post is inly for developer, add + so that he/she could see this
well u may make so that achievments give us smth good like additional points. or other way there is no point in aiming zombies` heads for 100 HS achievment - it is much more easier and better to shoot their leg. and make that santa to use some diet :D
hhahaha :D, damn man, yeah you found it out, its way better killing the zombies at the leg. =D Thats the only reason i added the achievement :P, you'd make a good game designer/tester. Will ping you when I'm gonna start testing my next game =D
 "ZombieInvaders"){kind=icon}
 "Monster Mowdown 2"){kind=icon}
 "Mario & Sonic Zombie Killer"){kind=icon}
 "Christmas Archer"){kind=icon}
 "Kingdom Rush"){kind=icon}
 "Santa Kills Zombies 2"){kind=icon}
 "Santas Battlefield"){kind=icon}
 "Infinite Dungeon RPG"){kind=icon}
 "Search and Destroy!"){kind=icon}
 "Diamond in the rough"){kind=icon}
 "Trapped with Zombies"){kind=icon}
 "Big Battle: Tanks"){kind=icon}
 "Blast Em!"){kind=icon}
 "Wolf VS Zombies"){kind=icon}
hhahaha :D, damn man, yeah you found it out, its way better killing the zombies at the leg. =D Thats the only reason i added the achievement :P, you'd make a good game designer/tester. Will ping you when I'm gonna start testing my next game =D