Thanks, I'll take a look at it.
Let me ask you this, to confirm a suspicion I have:
Have you seen a popup for any achievements received? And if not, can you check out the game stats page and see if there are any achievements it says you've received?
I got a blue screen error when I went to check my achievements. Wild, alright. Here it is:
Error
gamestates/gamestats.lua:163: bad argument #1 to 'sub' (string expected, got boolean)
Traceback
[C]: in function 'sub'
gamestates/gamestats.lua:163: in function 'switch'
gamestates/menu.lua:197: in function 'keypressed'
gamestates/menu.lua:232: in function 'mousepressed'
main.lua:126: in function <main.lua:125>
[C]: in function 'xpcall'
I released a new update that should fix the achievements crashes, anyway.
Messing around with your save file I couldn't get any silent crashes to occur, though. Do you happen to remember what you might have been doing or what might have happened soon before the crashes? Your save file was on level 3, were they any more/less frequent on any of the levels?