This game was developed in 3-4 weeks and very rushed at the end.
The aim was to create something fun, that looked pretty good and all for under 200k.
I haven't done much testing on low-end machines but I fear you'll need a decent processor for this to work smoothly.
Top score is currently over 30,000 getting to level 60, but you'll have to play at http://www.cedalion.co.uk/loki/cat_fs.asp to register a high score.