There's quite a lot in this game! Extensive skill tree, multiple levels, multiple enemies.
I ended up not being able to see as much of it as I'd like though, since so many rounds were required to make real progress. I feel like the game would benefit a lot from either faster move speed on calli, a longer round timer, or both. In a lot of cases I only had time to kill 2-3 enemies before I needed to go to a portal to end the round, at which point I'd just start another round immediately since 2-3 enemies didn't give me enough resources to buy any upgrades. This messed with the flow of gameplay since I was having to go back to the menu and start again instead of being able to keep playing till I had a good number of items to spend.