You're not stable yet, since volume goes WAY up once you're in the Top 25 of a category. It then goes through the roof when you're in the Top 5. Even though you're seeing great sales now, you need to push into the Top 25 to see phenomenal sales. To be safe, get into the Top 15, that way you have more margin to work with in the day to day rank fluctuation.
Drop to $1.99 for two days and see if you continue gaining in rank. We were able to blast past tons of 99 cent apps with Free Audiobooks at $1.99 and get to #2 in Books within three days, so it's not a big deal. Games is way different from books, though, so try $1.99 for 2-3 days, then give 99 cents a shot.
Also, grab Applyzer (applyzer.com) for this, it's awesome- hourly rank tracking for $3/month. If you stall out or otherwise see your rank starting to slide, drop to 99 to give a boost. That recovers your momentum and, after 24 hours or so, you can put your price back to $1.99. There's a LOT more to rank management, but this is how we're able to maintain the #1 and #2 paid positions in Books for weeks on end, barring when Apple features a competitor.
Good luck :)