Intense play. Beat as many aliens and slimes as you can through every level.
Collect Attachments. Gain special weapon attachments from enemy drops with different effects to aid you in skirmishes.
Build Turrets. Collect enemy drops to craft and build turrets that dominate the playing field to eliminate on coming enemy waves to give you an upper hand.
Health Packs. With each enemy you kill you can also pick up health drops to replenish you.
Play as a robot fighting off waves of aliens and slimes in an endless loop of levels. Gain modular weapon attachments dropped by enemies when they die and use them to not only upgrade your own gun but also craft turrets that dominate the playing field which help you kill enemies.