Had fun. - tested Linux (Debian)
Would consider making game playable 100% on keyboard.
At first I was confused how should I know I'm getting attacked but than I realized that there is indicator at the bottom. People will miss it, idk if you should make it bigger or make a text appear like "new wave approaches" but would def add a sound.
Everything is gray in shop. Mark items I can afford so I jump in and see it, normally I would suggest color but you have limited color palette.
Why those circles around cartridges have collision - it was annoying
When I unlocked Fire as first item I was confused why I can't use it. Than I realized I have to pick it up and keep doing it, I got used to it but can Items regenerate at the end of the wave?
Time pause in shop is nice, pausing fire/enemies/player/projectiles - sure. But letting resources drag into our base without me having to pause/unpause/pause would be nice. Just make resources ignore the pause (or our base that sucks them in)
Tier 3 tree (oak?) - I was not sure if it's a tree looking at the sprite.
I wanted to move like 6 items but got blocked by collisions, so I dropped them and picked some again, for some reason character didn't pick up items that were closest to him, idk what is the rule to choose what item he picks up but I would recommend smallest distance.
After getting 4-6 cartridges I would consider something like compass - shows direction to closest cartridge, when I was searching for the last 2 it got a bit annoying.
Fire item - OP. Didn't realize it has throw range (does it need it?), threw it on the floor by accident and couldn't pick it back up.
Light - Nice
Carry capacity - put only one point into it. Because collisions are so big I would lose blocks if I tried to take more than 5 and increasing carry capacity wouldn't make me route less bc I would take 2 routes for 7-12 items, so to make it worth I'd have to be able to take everything at once.
Rotation speed - 3 levels in I was afraid to put extra point in bc it got harder to aim and rotation 180 deg was fast enough
Vision range - put only one point in it. If it moves enemies further away I would consider it more.
Healing and HP up - If you invest resources into it means you already are losing and you lose even more by taking it than damage and other options. Heal costing different currency was good.
If you're wandering about economy I finished game with a lot of circles, at the end I would ignore them and move as many squares as I can.