Plaigerized
This is just blaitant, bold face plaigerizm. The concept is identical to body ladder. Even the music was similar.
I assume what you were trying to do was improve the old version. Not only did you fail in creating something that was unique you failed to accomplish the goal you had in mind. The aiming was bad- in the original you could use the mouse to aim. The weapon selecting was bad- I found myself avoiding flamethrower power ups cuz the shotgun was so much better. The art was bad- In attempting to improve the old one you cut corners on something that is highly important to making a good game.
I hope in the future you create some of your own ideas. Or at least wait till people forget about the game that your copying.