A really good start for an alpha build I'd say, I had fun playing this! 

The physics seem to be a strong point, the bounciness of the slam attack and exploding barrels mechanic is quite satisfying, the placement of spikes and cover to create kill-zones was cleverly done too. 

I do agree with other folks who've commented here that player feedback and reloading could use some improvement. A simple health bar and ammo-left indicator would make a world of difference. The weapon swap mechanic would feel a lot more intuitive using the left mouse button / right mouse button to switch between weapon types, or even just to trigger each type. Moving my hand to press 1/2 while trying to move to avoid enemies with WSAD was frustrating. I think with a little refinement you'll have a solid core loop for a fun top-down shooter with lots of potential! 

1. about core mechanics,  2) about player status feedback

Ad1) When I am shooting it feels good, when ammo zeroes out it gets boring, reloading time feels too long for me, especially since I think the reloading should be continued in the background even when you change to the melee weapon. During gameplay I would like a scenario when I shoot the whole magazine, then change to melee weapon, do 1-2 slams, and then change to range weapon with a full magazine but at this point when I change to the shooting weapon it still reloads and it is frustrating, like the action is slowed down because of that.

Ad2) Until there is no health bar or reloading animation or ammo magazine status I would propose even simple writings, Health X, Reloading timer showing value from Y to 0.

Another thing with weapons swapping. I notice that often when I want to swap the weapons I also want to be in constant movement, but when playing on a keyboard I have to move fingers from AWSD to 1 or 2 and it slows down the action or makes my dodging capability worse. At the same time, the right mouse button is still not used. I do not know how many weapons you would like to have in the future but if the weapons loadout will be 2 at a time then maybe the weapon swapping should be done automatically when using the Left Mouse button and right mouse button, RMB could swap to melee weapon and then do the slamming. Or both weapons should be visible all the time just make shooting with LMB and melee attacks with RMB.

Shooting and slamming felt good as they are. As long I had enemies to shoot and Enemie’s missiles flew in my direction ( so I needed to make dodges) it was great. Good job with the developed core mechanics!

I enjoyed this game quite a lot! Even though there is "little polish" there is quite a bit of fun. Sure, the enemy path finding was simple and they got stuck (which I abused), but that is easily fixed with navmesh movement. Crisp sound and great movement feel. Also, nice touch with the exploding "barrels" spread around the level. They will come in handy on harder levels.

I found the reloading aspect of the game a bit frustrating at first without some feedback since I didnt know how much ammo i had left, but I quickly learned to deal with it. 

I was also spawned inside the spikes at one point which was funny :D haha 

Overall though, I really enjoyed the game. Great job!