TPGK, Villain moves in on river

[maryfield48]

PokerStars No-Limit Hold'em Tourney, Big Blind is t30 (9 handed) converter

CO (t1270)
Button (t1400)
Hero (t1720)
BB (t1860)
UTG (t1480)
UTG+1 (t1450)
MP1 (t1280)
MP2 (t1690)
MP3 (t1350)

Preflop: Hero is SB with J[img]/images/graemlins/diamond.gif[/img], A[img]/images/graemlins/spade.gif[/img].
<font color="#666666">4 folds</font>, MP3 calls t30, CO calls t30, Button calls t30, Hero completes, BB checks.

Flop: (t150) A[img]/images/graemlins/heart.gif[/img], 6[img]/images/graemlins/diamond.gif[/img], 4[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(5 players)</font>
<font color="#CC3333">Hero bets t100</font>, BB folds, MP3 folds, CO calls t100, Button folds.

Turn: (t350) 2[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">Hero bets t210</font>, CO calls t210.

River: (t770) 3[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(2 players)</font>
Hero checks, <font color="#CC3333">CO bets t930 (All-In)</font>, Hero?

This was fairly early in a PS $11. Earlier Villain had cost himself a couple of hundred when he kept betting into his opponent holding 2 to a 3456 board. Of course opponent had a 7.

My thinking pre-flop was OOP with all these limpers I didn't want to get married to the pot, so I decided to keep it small. Is that terrible?

So I flop TP, and bet the flop and the turn. I put Villain on a weak Ace. I don't really know what I was thinking with the river check.

What am I to make of his river all-in?