Two quick suggestions.
1. Nerf spike damage. One damage is sufficient on Normal. Falling into a spike pit shouldn't remove 1/3 of your health.
2. Make the up arrow the jump. A to fire. S for sword. D to interact.
The main problem with this game is that you lose points when you move up. Eventually tier 1 will be all players with 300+ points making it impossible for anyone else to reach it and stay.
This game is a classic example of good concept, bad realization. Everything about it seems to be good until the game starts. Then it fails these two reasons:
1. Troop movement doesn't work because they stop to shoot on the way to their target. That might be good in some circumstances, but not when you're trying to move them to cover. This could be remedied if the developer allowed the user to choose how they moved. Quickly, Cover fire, crawl, exc.
2. The AI is laughably bad. Troops have no rhyme or reason to who they shoot. I had an enemy walk through my bunker (which had a machine gunner and another troop) and continue off the screen. They were not shot at once. i had an enemy machine gunner set up in the middle of the screen with no cover start taking my troops one by one. But they decided to shoot other people instead. You should be allowed to choose who your troop shoots or atleast choose how they choose. ie. nearest, best weapon, highest ranked.