LMB Nearing "Feature Complete"

I recently posted Laser Missile Bomb on the site TIGsource and got some good feedback; specifically concerning some lag and low framerates on older computers. I haven't completely solved the lag issues, but I'm making progress... unfortunately it's just a very physics-heavy game. I've changed the speed of the robot a bit and made him a little more responsive to input so he doesn't feel quite so floaty and the blocks can be pushed faster also.

I've also added in a few general features such as a start screen with New Game, Continue, Level Select, and Credits. Right now only the New Game and Continue buttons are functional and the game doesn't actually save your progress if you navigate away from the page and return; however, exiting back to the main menu and pressing Continue will bring you back the the farthest level you progressed to. Actual saving will be implemented soon as will the Level Select and Credits buttons.

Please keep the feedback coming. I will do my best to address every comment and change the game based on your input. Thanks!

Here is the link to play the current version: https://sites.google.com/site/lasermissilebomb/current-build