I really liked the demo, but I did feel that it ended a bit too short as getting the upgrades with the points was hard after they increased the cost progressively. I think allowing players to get that easier would be good, and then ramping up the spawning of cubes with it. I also think adding some sort of way to progressively see the higher damage values compared to the overall health of enemies further in (Like a level system where killing a boss increases your level). Overall though, I had a lot of fun, even if it was short.