Nice art, The magnet upgrade did help a ton. I like the idea that getting a combo of guys lets you interact or perform additional actions within the game in addition (or contribute) to scoring points ( its like getting one of those bomb tiles in match 3 games that clear out an entire row )
I think having more combos of these little guys would be something cool. Additionally (maybe) discovering these interactions while playing the game would be cool.
Anyways, this was fun, nice game!