During one update, the "Ring Ring" upgrade's name was changed to "Double Rings", likely to make its purpose more apparent (purchasing it doubles each ring the player collects in-game), though the internal files still call the upgrade "Ring Ring".
The game's executable also has lots of commented-out text:
<!-- magnet: lvl1 unlococked -->
<!-- bounceback: lvl2 -->
<!-- bomb: lvl5 -->
<!-- shield: lvl8 -->
<!-- ringtime: lvl11 -->
<!-- blastoff: lvl14 -->
<!-- Powerup skip mission -->
<!-- characters level locked and visible in game -->
<!-- characters level locked and visible in game - discount A -->
<!-- character reserved for gift or promotion -->
<!-- character reserved for gift or promotion - Discount A -->
<!--Funds-->
<!--Rings discount alternativeA-->
<!--Rings discount alternativeB-->
<!--Rings double-->
<!-- special case, this will award you the cost, rather than deduct it -->
<!-- Wallpapers -->
<!-- validators and parameters
All validators must be succeed for a hint to appear
<storecheck checkFunds="true" checkUnlocked="true" checkUnequipped="true" />
check funds = fail if there is not enough cash to buy the item in storelink
check unlocked = fail if the item in storelink is locked
check unequipped = fail if the player has the item in store link equipped.
<rankcheck min="1" max="22" />
fail if the players ranks is not between min and max values
<zonecheck zone="0" check="true"/>
fail if the result of the current zone index compared to "zone" does not equal the value in "check"
<inifinitecheck check="true" />
fail if inifinite mode is not set to the value in "check"
<deathcheck spikes="true" enemy="true" fall="true" boss="true" />
specify which death states will allow the hint to be displayed.
-->
<!--Fall-->
<!--Generic advice, these are placed inbetween the specific messages to break up the repetition -->
<!--*new icon requested* -->
<!--Generic advice, these are placed inbetween the specific messages to break up the repetition -->
<!--Generic advice, these are placed inbetween the specific messages to break up the repetition -->
<!--Generic advice, these are placed inbetween the specific messages to break up the repetition -->
<!--Killed by enemy-->
<!--Generic advice, these are placed inbetween the specific messages to break up the repetition -->
<!--Generic advice, these are placed inbetween the specific messages to break up the repetition -->
<!--Eggman-->
<!--Generic advice, these are placed inbetween the specific messages to break up the repetition -->
<!--Spikes-->
<!--Generic advice, these are placed inbetween the specific messages to break up the repetition -->
<!--Generic advice, these are placed inbetween the specific messages to break up the repetition -->
<!--Enemy-->
<!--Eggman-->
<!--Spikes-->
<!--Upgrade advice should only appear if the player can afford the upgrade and already has unlocked the item-->
<!--Powerup hits to the top so that they are chosen as soon as the powerup becomes unlocked-->
<!--normal generic advice is a lesser priority but will be chosen first due to other content being locked-->