Wearing the right foot wear on the paintball field is very important.  Make sure you get what you need for what kind of game your playing.  If you're playing woodsball, I would recommend buying a good comfortable pair of light weight boots; if speedball is your game, I recommend wearing an old, or cheap pair of cleats.  They do make cleats just for speedball, but I would not recommend buying them unless you play so much that you would need them all the time.  Do not wear sneakers during a game!  I see kids all the time tripping and slipping because they wear sneakers at a muddy woodsball field.  Buy a boot, or cleat that is comfortable, the last thing you want to do is get nasty blisters on your feet from loose boots.  Paintball is not a fashion show, wear what fits your needs, not just what looks good on you.  Make sure to also wear thick, high socks; do not wear ankle socks with boots.  The number one thing to remember is safety and comfort, so get whatever is right for you. 
Mike Morton, Team Trinity