a little humour, attention to detail and varied, non-repeating enemies. (e.g. no green, blue then purple goblin which is essentially fighting the same thing with more hp/dmg) Upgrade trees are friendly and yet allow for customisation to a playstyle. Was this playtested extensively? It feels like it was.
Needs better targeting for AI allies. They should attack the nearest enemies, not run half the screen towards target A, then if A gets killed, run backwards half the screen again towards target B, all the while ignoring enemies along the way.
 "Platform Racing 2"){kind=icon}
 "Death vs Monstars 2"){kind=icon}
 "Crazy Digger 2 Level Pack 2"){kind=icon}
 "Cyber Chaser"){kind=icon}
 "Road Of Fury"){kind=icon}
 "Witch Hunt"){kind=icon}
 "Mighty Knight"){kind=icon}
 "Toss the Turtle"){kind=icon}
 "The Peacekeeper"){kind=icon}