I got sucked into this and played it for far longer than I expected I would! Overall I had a great time and from a dev perspective I'm amazed by what you managed to achieve in the time you had!
Unfortunately my running experience was one of minor frustrations, most of which stem from the starting speed. Game balance is a difficult art and as such this is somewhat my personal taste, but the slow speed + quantity of enemies spawned means it is near impossible to collect long-range experience orbs without the relevant upgrade. This means I lack upgrades and as such the number of enemies alive grows far faster than I can kill them.
In the end, what usually kills me is (I think) a physics bug: enemies partially stack up on each other as they turn to face the player, then explosively move away to ensure that they have their own space. The outcome for the player is that the basic enemies essentially start dashing towards the them, faster than the player can move. The only time I managed to reliably avoid this was by luck when I could stack Celerity 3 times.
I don't want your takeaway from my comments to be negative, or that I didn't have a good time - I spent the better part of 45 minutes playing, and for good reason! The upgrades are creative and I really like how distinct the starting weapons/powers are! It's a great game and with a few small tweaks I think could be absolutely fantastic fun!