Great game, there's quite alot of potential here. I'll leave a list: campaign mode, more maps, weapon comparisons (when you to go select a new weapon, one part of the screen displays your current weapon and it's stats, and hovering over another weapon displays that one's stats for you to compare), multi-height maps (pointing straight in one direction tends to get a bit tedious after awhile), larger variety of music and being capable of purchasing armor which actually affects your stats (e.g. you can wear heavier armor that slows you down or you can use lighter armor which allows for more mobility but leaves you more vulnerable).