I'm joining the extended-BASIC mix as well! Simul 2 is my complete rewrite of my multitasking game Simul (from scratch, using absolutely none of my code from before).
Simul 2 is a game of multitasking. In Stage 1, you switch among six minigames (Pong, Falldown, Avalanche, Jump, Tunnel, and Obstacles), playing each one for a few seconds before switching to the next, Your goal is to simply keep alive in six games in a row.
In Stage 2, you do the same thing—but with two games on the screen at a time. The game on the right is controlled by the normal arrow pad (up and down, or left and right), while the one on the left is controlled by four keys on the left side of the calculator (either MODE and X,T,θ,n for up and down, or ALPHA and STAT for left and right).
Pass that and you get to Stage 3, where the left half of the screen is split into two quarters, one controlled by MODE/X,T,θ,n and the other by ALPHA/STAT. The right side still contains a single game controlled by up/down or left/right arrow keys.
Six more sets of games, and you get to the final stage, Stage 4. As you can probably tell, that's playing four games on a single screen. At once. Beat six sets of that, and you win; then the game goes into infinite mode, so you can keep playing that four-game awesomeness
For those of you who have played (or tried to play) the original Simul, know that Simul 2 is much more playable. After many failed attempts I managed to get to Stage 4 at medium speed (out of three speeds: slow, "For the casual multitasker"; medium, "For the more courageous ones"; and fast, "For the insane"). You're allowed to die as many times as you need to, but remember that you must pass six sets of games in a row to pass each stage. It also lets me implement a new high-score system that wasn't there in the first version, based on the number of times you died and the speed you used.