Thank you for playing and for the feedback!
A wide variety of weapons will pretty much be the point of the game, its very easy to add new ones (just have to write more interesting logic other than projectiles). It will be closer to something like Borderlands later and being able to inspect their exact stats.
Which ties into why there's a portal before going to the next level; usually you won't have much time while there are enemies to look at and try out guns - also to collect other drops (will probably make it so the portal pulls all items towards it).
The small pushable rocks are there to be a bit annoying and hinder your movement hehe. Also to use as cover and slow down enemies if you take advantage of them. However, currently the generation of them is not balanced at all, so its very possible that you got levels generated with way to many of them... They're supposed to be a small unique element of this map type, but right now its the only type of map.
You're definitely right about the hit feedback and I will improve it.
The minimap is honestly not meant to be that useful, mainly because I don't want players staring at it instead of the actual game. The primary purpose of it is to easily see where enemies are when levels start to get big. I will think about adding a skill for seeing walls on it though.
Accidentally running into a dead end and getting punished for it I see as intended though, but there is supposed to be ways to get out of it. Right now there aren't that many though; mainly escaping out of such a situation by destroying walls and making your own path (explosions do way more damage to the environment). Other ways, which I have yet to implement, will be for example teleporting, pushing enemies away (the primary fire of the shieldgun can do this to some extent, if you keep firing and charge through a horde of enemies you can often get through, but you'll probably get damaged), phasing through them, etc.
Basically, I hope some design choices will make more sense once I add more content.