A simple hilo game using Gum (https://github.com/charmbracelet/gum)

hilo.sh

#!/bin/bash
clear
# init colors
FG="#00ffff"
BFG="#00ff00"
# if you wonder why true is in there https://www.shellcheck.net/wiki/SC2015
gum confirm --default --affirmative="Play now" --negative="Dump source first" --timeout=10s "Would you like to view the source code before playing?"  && true || (  gum format -t code <"$0" )

# get initial info
gum style --foreground "$FG" --border-foreground "$BFG" --border double --align center --width 64 --margin "1 2" --padding "2 4" \
    "Welcome to Hackaday's HiLo Game!" \
    "First, tell me your name and then pick the higest number YOU want me to guess"
echo "What's your first name?"
NAME=$( gum input --placeholder="Tell me your name, please..." )
NAME="*$NAME*"
if [ "$NAME" == "**" ]
then
    gum style --foreground "$FG" --border-foreground "$BFG" --border double --align center --width 64 --margin "1 2" --padding "2 4" "Oh well, see you later"
    exit 0
fi
echo "Hi $NAME. Now tell me the highest number you might pick. Then pick a number less than or equal to that and I'll guess it." | gum format 
MIN=1
MAX=X
while [[ "$MAX" == "X" || "$MAX" == "" ]]
      do
	  MAX=$( gum choose --selected="100" 100 1000 10000 exit )
      done
	      
if [ "$MAX" == exit ]
then
    gum style --foreground "$FG" --border-foreground "$BFG" --border double --align center --width 64 --margin "1 2" --padding "2 4" "See you next time"
    exit 0
fi
TRUEMAX=$MAX  # save for next game

# here's the main game loop
while true
do
    CT=$(( CT + 1 ))   # number of guesses
    if [ "$MAX" -le "$MIN" ]  # detect cheating
    then
	gum style --foreground "$FG" --border-foreground "$BFG" --border double --align center --width 64 --margin "1 2" --padding "2 4" "I'm not playing if you are going to cheat!"
	exit 0
    fi
    G=$(( (MAX+MIN)/2 ))   # calculate guess
    gum spin -s meter --title "Thinking..." sleep 2  # make it look hard
    echo "Well $NAME... I guess $G" | gum format
    RES=$( gum choose low high right quit )
    if [ "$RES" == quit ]
    then
	gum style --foreground "$FG" --border-foreground "$BFG" --border double --align center --width 64 --margin "1 2" --padding "2 4" "That was fun anyway"
	exit 0
    fi
# got it!
    if [ "$RES" == right ]
    then
	gum style --foreground "$FG" --border-foreground "$BFG" --border double --align center --width 64 --margin "1 2" --padding "2 4" "Yeah! I knew I would get it! Took me $CT tries"
	CT=0
	MIN=1
	MAX=$TRUEMAX   # set up for next game, maybe
# continue can't return false (https://www.shellcheck.net/wiki/SC2015)
	gum confirm "Play again?" && continue || break 

	exit 0
    fi
# didn't get it, so adjust
    if [ "$RES" == low ]
    then
	MIN=$G
    fi
    if [ "$RES" == high ]
    then
	MAX=$G
    fi
done
# exit 
gum style --foreground "$FG" --border-foreground "$BFG" --border double --align center --width 64 --margin "1 2" --padding "2 4" "That was fun!"
exit 0