This game is okay for what it is. It's been a long time since seeing a 3D game with this much chance of being good, but it falls flat on 3 main categories:
1. Placement of Enemies - On occassions I have to jump over the enemies if they come from the top or side and did not shoot them. However if they come from the bottom or top end you WILL die because you cannot dodge them in any way, slow down, aim, or even shield until you get enough money for it.
2. Options - Your only option is the shoot the enemies, some can trap you and you have no way to evade them like a missle drone jumping and shooting right before you jump a gap. You cannot slide nor double jump or at least dash which would have added enough depth for this type of game.
3. Shooting - You only shoot forward saying a big f*ck you to the awkwardly (you shall not pass) enemies. The upgrades are not bright enough to be easily seen especially with all of the extra colors in the background and enemies. To add insult to injury you have a distance counter for a game that you can run out of ammo for, which is simply bad game design overall.
The game would need just a few simple tweaks, but would put you off very easily the way it is now. I understand the game is for trial error buy and improve, but this game should give you the chance to do improvements without buying first so you feel like the only thing holding you back is your own skill. I like the concept and work in it, but every money you get is quite infrequent from the start and your health is too small for this to be worth anyone's time, especially when the game is what kills you and not your own incompetence.
2/5 Could be worse, and easy way to improve the game overall.