That's very nice for a simple game, but there are flaws you need to work out.
1. Reload button should be "R" button like all shooting games, do not use the Tilde.
2. Instructions are recommended in the main menu, even newbies get confused on that icon above.
3. Key customization, like the reload problem, I prefer to use "R" as my Reload button, not the Tilde.
Overall, good game, including music, graphic and such.